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  • Public defence: 2024-05-28 14:00 hörsal 9, hus D, Stockholm
    Goodrich, James
    Stockholm University, Faculty of Humanities, Department of Philosophy.
    Self-Defense Without Deontology: Groundwork for a Consequentialist Ethics of Harm2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Can those attracted to Act Consequentialism provide a plausible theory of the ethics of self-defense? In this dissertation, I argue they can. In Chapter 1, I summarize my motivations, approach, and conclusions. In Chapter 2, I answer an initial objection to the whole of my project. Roughly put, the objection is this. We know moral rights are needed to make sense of some of the most basic theoretical claims about the ethics of self-defense. If fundamental moral rights are an indispensable part of the best theory of the ethics of self-defense, then Consequentialism is a nonstarter, no matter what is said in this dissertation. I argue that we’re wrong to think that fundamental moral rights are indispensable to the ethics of self-defense. In Chapter 3, I defend "Justicism," the view that an act is morally permissible if and only if that act brings about at least as much aggregate justice-weighted well-being as any alternative to that act. My defense of Justicism involves several distinct steps, including offering a rationale for Justicism, defending an interpretation of various constraints on defensive harm, and offering a more precise toy model of how Justicism works. One limitation of this chapter, however, is that it assumes a tight connection between facts about justice and facts about individuals who are responsible for attempting to harm others without provocation. In Chapter 4, I attempt to explain the tight connection between justice and responsibility I assumed in Chapter 3. I argue against a desert-based interpretation and in favor of the following fairness-based interpretation of the role of responsibility and fairness. I call this view, "the Fair Opportunity View" and the combination of Justicism, the Fair Opportunity View, and the claim that justice-weights are a function of facts about fairness, “Luck Utilitarianism.” Luck Utilitarianism, I propose, is an independently plausible theory and can explain most of our intuitions about the moral permissibility of harming others in self-defense. In Chapter 5, I respond to an objection to any Justicist theory of the ethics of self- defense. The objection, roughly, is this. Some of our intuitions about the ethics of self-defense involve all and only innocent people. As such, the Fair Opportunity View is of no help to explain why acts of self-defense are morally impermissible when they promote aggregate well-being. I consider a range of responses, concluding that assigning disvalue to exercises of domination provides the most plausible way of explaining our intuitions about the impermissibility of defensive harm against innocent people within a Consequentialist framework. In Chapter 6, I summarize my conclusions and attempt to further bolster my main argument for the plausibility of a Consequentialist theory of the ethics of self-defense. 

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  • Public defence: 2024-05-30 13:00 lärosal 4, hus 1, Albano, Stockholm
    Sagués Carracedo, Ana
    Stockholm University, Faculty of Science, Department of Physics.
    Chasing Cosmic Rarities: Kilonovae and Gravitationally Lensed Supernovae in Optical Surveys2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis focuses on two important topics in astrophysics: the detection of kilonovae (KNe) and gravitationally lensed supernovae (glSNe) in optical surveys. In the first part, the study quantifies the impact of survey depth and choice of filters on the detection probability of KNe. The results highlight the importance of accounting for asymmetries expected for KNe, and despite several search campaigns, no KNe were detected by the Zwicky Transient Facility (ZTF). Nonetheless, non-detection studies provided meaningful constraints on the luminosity function and on the rates of KNe. The findings contribute to advancing our understanding of these rare, fast, and faint transients. I also discuss the improvements in measuring the Hubble constant with follow-up data of KNe, including broadband photometry and spectrophotometric data from the upcoming IFU instrument MAAT. 

    The second part of the thesis focuses on gravitationally lensed supernovae. The ZTF survey was expected to detect more than one strongly lensed supernova per year, but only one was identified in the first five years. The study presents simulations of lightcurves for lensed supernovae and new rates based on realistic survey simulations for ZTF. Optimal cuts to distinguish lensed supernovae from normal unlensed supernovae are also provided. The thesis discusses time delay and lightcurve modeling for the one event found during ZTF, SN Zwicky, and the lessons learned from it.

    The techniques developed in this thesis can be applied to future surveys to increase the detection rate of KNe and glSNe. These events and their underlying physics provide valuable insights in cosmology.

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  • Public defence: 2024-05-31 08:00 CCK lecture hall, Solna
    Kalholm, Fredrik
    Stockholm University, Faculty of Science, Department of Physics.
    Averaged linear energy transfer and other beam quality descriptors in relation to proton relative biological effectiveness2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In clinical proton radiotherapy, a fixed relative biological effectiveness (RBE) of 1.1 is commonly utilized, assuming a consistent 10% increase in cell inactivation effectiveness compared to photons, regardless of proton energy and cell type. While this fixed RBE assumption has generally led to satisfactory clinical outcomes, various studies based on both in vitro data and patient outcomes suggest that the RBE may actually vary with proton energy. However, there is no widely accepted method to quantify this variability using a specific RBE model. In clinical practice, concerns regarding RBE variability are typically addressed by reducing the dose near the end of the proton range, where the variable RBE is presumed to be highest, particularly near distal risk organs.

    Many proton variable RBE models have been proposed historically, mainly based on in vitro data. Most commonly, this involves describing the α and β parameters of the linear quadratic (LQ) model as a function of a chosen radiation quality metric. Typically, this metric involves an averaged value of linear energy transfer (LET) at a given location. By comparing the obtained α and β values against corresponding parameters obtained under reference conditions (typically megavolt photon irradiation), the RBE value can be modelled.

    While the radiation quality metric used for proton variable RBE models typically is dose-averaged LET (LETd), the details on how the averaged LET value has been calculated or determined are often not fully provided, possibly introducing a source of error in the estimated RBE value. This can vary with respect to the averaging method (typical dose- or track averaging), included particles (only primary, or also including secondary protons and/or ions) and other aspects. Furthermore, while LET is the most commonly used beam quality descriptor, other quantities exist such as Q and z*2/β2, renamed in this work as Qeff. These alternative metrics have been shown to better correlate with RBE across different particle species compared to LET, and can potentially perform better for a single particle species as well. However, these has so far not been systematically tested or verified. 

    Paper I investigates which kind of averaged LET is provided in the scientific literature for the purpose of RBE determination, for both protons and other hadronic particles. It also attempts to quantify the corresponding impact to the calculated RBE values. Paper II investigates which beam quality descriptor is most suitable for predicting RBE by simulating the experimental setup of recently published high throughput in vitro cell survival studies for RBE determination by a Monte Carlo particle transport code, and fitting parameters to a phenomenological LQ-based model based on the cell survival data. Different variants of LET, Q and Qeff are included, to generate both linear and non linear variable RBE models. Paper III explores if novel averaging techniques, deviating from conventional linear weighing when compiling the LET spectrum, can improve RBE predictions, while paper IV finally investigates if a binary weighing technique (dirty dose) can be utilized as a radiation quality metric.

    In paper I, it is shown that averaged LET for the purpose of RBE determination is, typically, not entirely well defined with a significant minority not mentioning which averaging method is used, and a majority not mentioning what particles are included when averaging. The impact of using different definitions for proton variable RBE models is, in most cases, small, unless heavier secondary particles are included. In paper II it is shown that Q and especially Qeff are expected to better predict RBE compared to LET by a statistically significant margin, for both linear and non-linear models, suggesting they are likely to be more suitable beam quality descriptors to use in a LQ based phenomenological variable RBE model. The results from paper III suggest that performing a non-linear weighting when compiling the LET spectrum into a radiation quality metric improves the performance of the variable RBE model, suggesting a non-linear underlying RBE(LET) relationship of individual protons. Paper IV finally shows that variable RBE models based on the pragmatic dirty dose approach performs on par with conventional radiation quality metrics, while offering improvements by enabling both simplified calculations and efficient measurement techniques.

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  • Public defence: 2024-05-31 10:00 hörsal 8, house D, Stockholm
    Williams, Lawrence Joseph
    Stockholm University, Faculty of Law, Department of Law.
    Transfer Pricing and the World Trade Organization Agreement: The compatibility of transfer pricing principles contained in Bilateral and Multilateral Tax Treaties with the WTO non-discrimination norms2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The overall purpose of my research is to explore the potential overlaps, interactions, and conflicts between bilateral and multilateral tax treaties within international trade law and transfer pricing. More specifically, to determine whether WTO Members when applying transfer pricing principles contained in bilateral tax treaties based on the OECD Model Tax Convention and the Multilateral Convention to Implement Amount A of Pillar One (“OECD MLC”) are remaining compliant with their WTO obligations. In doing so, the research provides further contributions on the horizontal coordination between international trade law and transfer pricing. 

    International trade law and transfer pricing are increasingly central to world politics, and it is essential that we obtain a better understanding of how these two areas of international law interact, overlap, and / or conflict. In the case of a treaty vs. treaty conflict, can such a conflict be justified?

    Countries can become WTO Members, OECD Members and / or members of the Inclusive Framework. These international bodies influence, coordinate, and / or harmonize legal reforms or formulate model laws (as is the case the OECD Model Tax Convention). Due to the lack of a single international parliament and countries operating and competing in a global context, countries need to accommodate multiple international organizations within public international law.

    The WTO Agreement cannot cover every policy area that touches on international trade. Thus, the research shows the importance of creating certainty within international trade law and transfer pricing through horizontal coordination between the OECD and the WTO. The research also builds upon the literature which shows that historically transfer pricing and international trade law have been developed in silos.

    The research concludes that there continues to be a lack of horizontal coordination between international trade law and transfer pricing during the drafting and implementation of the OECD MLC. The research shows instances of interactions, overlaps and conflicts between the transfer pricing principles contained in the OECD MLC and tax treaties based on the OECD Model Tax Convention with the non-discrimination norms contained in the GATT, the Subsidies Agreement, and the GATS. 

    With that said, the conclusion reached in the research is that despite the identified overlaps, interactions, and conflicts, such instances were found to be justified in the research. However, there remains a lack of horizontal coordination between international trade law and transfer pricing, which although did not result in an irresolvable treaty vs. treaty conflict in this research, remains an issue within public international law which should be focused upon more by policymakers and institutions such as the OECD and the WTO when proposing future reforms. 

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  • Public defence: 2024-05-31 10:00 Auditorium (215), Manne Siegbahnhusen, Stockholm
    Klingborg, Johan
    Stockholm University, Faculty of Humanities, Department of Culture and Aesthetics.
    Verkar film: 1930-talslitteraturen i det svenska filmnätverket2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The incessant distribution of moving images in the digital era not only draws attention to contemporary and future predicaments for reading and writing, but also makes it possible to recognize the ways in which literature historically has been contingent on optical media. This study examines how Swedish modernist literature in the 1930s responded to and was shaped by a situation in which moving images—following technological, discursive, institutional, and architectonic developments—had become a comprehensive aspect in people’s everyday lives. This film network brought about a biopolitics of the eye aimed at creating a homogenized observer within the population, who could serve both the emerging Swedish welfare state and an accelerating capitalist consumer culture. The study argues that the literature of the 1930s came to engage critically and productively with the network, while simultaneously incorporating—thematically as well as formally—its regulatory mechanisms.

    Methodologically, the study is grounded in media archaeology. Literary texts serve as accounts of the medial conditions that make this literature possible in the first place, functioning as “a discourse on discourse.” Hence, while the literature is analyzed from the perspective of the network, these analyses conversely also shed light on the network and its mechanisms for subjectivation. The study consists of four chapters with in-depth analyses of literary works in relation to particular dynamics of the network, while also considering the changes, openings, closures, and unforeseen effects that continually appeared within it.

    The first chapter shows how Karin Boye’s novel Astarte both reflects on and internalizes the changed conditions of perception that resulted from the breakthrough of electric light in the urban environment, with particular attention paid to its role in the movie palace. Conversely, the second chapter focuses on the part of the cinema building secluded from such perception control, namely the projection room, which serves as a precondition for the protagonist’s coming into being as a writer in Eyvind Johnson’s Künstlerroman Romanen om Olof. The third chapter connects Erik Asklund’s and Artur Lundkvist’s prose experiments in the early 1930s with the emergence of small-gauge film, which enabled a dispersed perception that was contrary to the strategy of the network. The fourth chapter, finally, shows how Boye’s novel Kallocain and Josef Kjellgren’s novel Människor kring en bro recapitulate the discourses and practices of educational film, which taught students, workers, and military personnel what was worth observing.

  • Public defence: 2024-05-31 13:00 sal G, Arrheniuslaboratorierna, Stockholm
    Karlström, Matti
    Stockholm University, Faculty of Humanities, Department of Teaching and Learning.
    Didaktisk modellering av lärarstudenters reflektiva praktik vid planering av undervisning i naturvetenskap2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The purpose of this thesis is to extract didactic models that can support science teacher educators in developing pre-service science teachers' (PST) professional reflection. Developing PSTs to become reflective practitioners has been a prevailing aim in teacher education since the 1980s. There have been many descriptions of what constitutes reflective practice and how reflection occurs. At the same time, there is no support for developing PSTs' habit of reflection; many models for reflection lack empirical support and PSTs perceive them to be lacking relevance. One activity that involves reflection is lesson planning, therefore I examined twelve pre-service science student teams' planning conversations based on the overarching research question of how PSTs' reflection can be described and modelled when planning science lessons. Didactic models were created through didactic modelling, a process in which I created descriptions of PSTs' reflections and extracted components that together form models thatsupport the reflection involved in planning teaching. The results show that the moments of reflection differed from other parts of the planning conversations. During these moments the PSTs changed their perspectives on how to plan teaching, and the quality of the PSTs' reflections also differed. In addition, the PSTs' reflections were guided not only by the purposes presented in the instructions for the planning work, but they also formulated their own questions that they needed to seek answers to before they could complete the planning task. Based on these results, I created three models that emphasize: (1) the importance of openness in a task in order for it to give rise to an opportunity for reflection, (2) the different purposes that guide the pre-service teachers' planning work, and (3) the importance of responsibility, open-mindedness and whole-heartedness for achieving a more complete reflection. These models highlight different aspects of PSTs' reflection and contribute to a deeper understanding of PST reflective practice. The models can be used individually or in combination to model PSTs’ reflective practice. The results contribute with both methods for studying reflection, descriptions of PSTs' reflection, especially in planning, an area that has not previously been studied separately in relation to reflection, and models of different aspects of PSTs’ reflection, providing support for the analysis and design of teaching that aims to develop PSTs as reflective practitioners.

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  • Public defence: 2024-05-31 14:00 FB53, Alba Nova University Centre, Stockholm
    Adler, Alexandre E.
    Stockholm University, Faculty of Science, Department of Physics.
    Polarized beams and the things they've seen: Modelling optical systematics for CMB polarisation experiments2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis, I describe several advances in modelling sources of systematic error associated with microwave telescope optics. Microwave telescopes observing the Cosmic Microwave Background (CMB) are a key tool in establishing and furthering the LCDM model of cosmology. In the near future, several telescopes will observe the polarized variations of the CMB with unprecedented sensitivity to search for traces of cosmic inflation and the epoch of reionization. My research questioned how various optical non-idealities would affect the accuracy of these experiments. In particular, my collaborators and I have examined potential systematics related to the beam/point spread function, the half-wave plate (a polarization modulator), and thermal ground emission. Our modelling efforts have relied on expanding the beamconv software library and on the GRASP beam simulation software.

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  • Public defence: 2024-05-31 14:00 Air & Fire, Gamma 2, SciLifeLab, Solna
    Marco Salas, Sergio
    Stockholm University, Faculty of Science, Department of Biochemistry and Biophysics.
    From pixels to comprehensive cellular atlases: Applications of in situ sequencing to understand tissue biology2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The development of single-cell RNA sequencing enabled the high throughput characterization of cell populations with unprecedented detail. Yet, it failed in capturing the spatial localization of individual cells. Overcoming this, different spatial profiling methods have been developed in recent years, with in situ sequencing (ISS) being among the most powerful solutions

    ISS is a targeted spatially-resolved transcriptomics method designed to detect the expression of hundreds of genes in situ in a single experiment. For this, ISS employs padlock probes, a type of oligonucleotide designed to specifically hybridize on the targeted regions, with rolling circle amplification and a combinatorial detection of the transcripts imaged. Due to its throughput and resolution, ISS is seen as a useful tool to create high content molecular maps of tissues, being of special use for building spatial atlases. However, due to its recent development, it’s still unclear how this should be done. The work presented in this thesis explores ISS as a tool for building large spatially-resolved atlases of cell types. 

    In paper I, we compare the performance of cDNA-based ISS with the High Sensitivity Library Preparation Kit, developed by CARTANA AB. We identify this product to be fivefold more sensitive than cDNA-based ISS due to its improved chemistry. In addition, we show that this increased sensitivity enhances the analytical capabilities of the resulting data.    

    In paper II, we build a topographic atlas of the developmental human lung. We identify 83 different cell types and states, including a novel type of GHRL-positive neuroendocrine cell. We further elucidate the developmental origin multiple populations, defining their location in situ and predicting potential interactions. 

    In paper III, we create a topographic atlas of the adult human lung. We combine multiple spatial transcriptomic technologies to generate spatial maps of the populations found in the adult lung. We decipher regional differences in terms of cell type composition and cell type-specific expression. Finally, we also characterize the spatial context of rare cell types.

    In paper IV, we employ large-scale data integration to construct a scRNA-seq-based cellular map of glioblastoma, an aggressive brain malignancy. In addition, we use ISS to generate single-cell resolution cell type maps of 13 glioblastoma patients, identifying consistent niches across patients and uncovering the cellular organization of these tumors. 

    In paper V, we explore the quality of the data generated by the Xenium In Situ Platform, a product based on ISS and commercialized by 10X Genomics. We explore the main characteristics of the data and benchmark it against other technologies. Finally, we also define best practices for the most common analysis done using these datasets. 

    Collectively, the studies presented in this thesis serve as evidence of the efficacy of ISS in constructing comprehensive cellular atlases with a single-cell resolution.

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  • Public defence: 2024-06-03 14:00 sal FB42, AlbaNova universitetscentrum, Stockholm
    Jacobsen, Sunniva
    Stockholm University, Faculty of Science, Department of Physics.
    Probes of New Physics: Signatures of new particles in extreme objects and ground-based experiments2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The Standard Model (SM) of particle physics is one of the greatest successes of the 20th century. It offers a beautiful description of the elementary par- ticles and their interactions based on symmetries and the breaking of them. Despite its success, the SM is regarded as incomplete both because it does not explain certain observed phenomena and because it exhibits fine-tuning prob- lems. This thesis explores how particles beyond the SM (BSM) interact with SM particles, and the signals we should expect from them. In particular, the classes of hypothetical, new particles denoted as "Weakly Interacting Massive Particles" (WIMPs) and "Axion-like Particles" (ALPs) are studied.

    This thesis consists of three papers, which all contribute to the search for new particles beyond the SM in different ways. The first paper focuses on a class of WIMPs called "inelastic DM" in which the DM particle must transfer onto a higher-mass state when it scatters off SM particles. In this paper, we have studied whether such a model can explain the discrepancy between the claimed DM signal in DAMA and the lack of one in other direct detection experiments. The second paper of this thesis focuses on ALPs and their signals in the γ-ray spectra of distant sources. ALPs and photons can oscillate in the presence of external magnetic fields, such as the ones that are expected to be present in the jets of blazars (active galactic nuclei). These oscillations should lead to an increased flux in the TeV spectra of these sources. In this paper we used data from the HAWC observatory to study whether the observed γ-ray spectra of these sources were in conflict with the expected spectra for different ALP models.

    The last paper in this thesis does not involve any new particles beyond the SM, but investigates whether current models of the isotropic gamma-ray back- ground (IGRB) is consistent with observations. Since searches for new par- ticles depend heavily on our understanding of astrophysical phenomena and the SM processes that take place, studies of these are important. The IGRB consists of all the diffuse γ-ray emission that cannot be assigned to individ- ual point sources. In this paper, we calculated the expected contribution to the IGRB from resolved blazars and found that this introduces an emerging tension between blazar models and observations.

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  • Public defence: 2024-06-04 10:00 sal FA32, AlbaNova universitetscentrum, Stockholm
    He, Yutong
    Stockholm University, Faculty of Science, Department of Astronomy.
    Cosmological gravitational waves and their interaction with large-scale magnetic fields2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The thesis explores the interactions between cosmological gravitational waves (GWs) and large-scale magnetic fields. GWs are radiation produced by spacetime variations of the stress-energy tensor. Due to the weak coupling between gravity and the matter sector, GWs are a unique messenger from the early Universe before the Cosmic Microwave Background (CMB). Magnetic fields are observed across the Universe from the scales of planets and stars to galaxies and clusters, as well as the voids beyond the clusters. The present-day large-scale magnetic fields are believed to have evolved from primordial seed fields via magnetogenesis mechanisms active during the cosmic inflation and reheating epochs or the cosmological phase transitions occurring at the electroweak (EW) or quantum chromodynamic (QCD) scales in the early radiation-dominated (RD) era. The production of stochastic GW backgrounds (SGWBs) can be expected from the primordial electromagnetic (EM) fields or magnetohydrodynamic (MHD) turbulence around the time of EW and QCD phase transitions. The SGWBs then propagate through the pre-CMB Universe until the present day, carrying with them essential imprints of the corresponding sources as well as the underlying gravity theory at the early times. Since MHD turbulence is ubiquitously expected in the RD era, their induced SGWB spectrum is extensively studied.In one aspect of the thesis, we demonstrate that the MHD-GW system exhibits features of modified gravity (MG) in terms of the spectral slopes and amplitudes of the relic SGWB. We compute the spectra of GWs produced by MHD turbulence at the EW and QCD phase transitions, assuming massive gravity and scalar-tensor theories as two MG examples. Then we comparatively analyze these modified GW spectra with their counterparts in general relativity, and determine their qualitative and quantitative differences due to three effective MG parameters – graviton mass, GW friction, and GW speed. These spectral features are compared against the existing pulsar timing array (PTA) measurement in the nHz band as well as the expected GW detection sensitivities of upcoming instruments such as the Laser Interferometer Space Antenna (LISA) in the mHz band and Square Kilometer Array (SKA) as a PTA. The framework is general and can be applied to non-MHD sourced GW spectra. However, fixing MHD sources yields concrete constraints on the effective MG parameters.The other aspect of the thesis concerns the interaction between SGWBs from the early Universe and large-scale magnetic fields in the post-CMB Universe, which would convert a fraction of the gravitons in the SGWBs into photons of the same frequency via the inverse Gertsenshtein effect. The graviton-induced photons could then be a source of spectral distortions of the blackbody CMB.This, in turn, would allow us to constrain the GW amplitudes in the MHz-THz frequency regime. The high-frequency GWs (HFGWs) correspond to new physics in the early Universe such as beyond-Standard-Model mechanisms or sub-stellar mass primordial black holes. We place constraints on the HFGW energy densities by exploiting the existing direct observations of the radio sky, measurements of the 21-cm signal upper limits, the kinematic Sunyaev-Zeldovich observations, and assuming that graviton-induced photons saturate all of the reported radio excess over the CMB. We also forecast the potential of SKA and proposed future CMB surveys as novel HFGW detectors, and show that they will significantly tighten the current constraints and bring us a step closer to detecting HFGWs.

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  • Public defence: 2024-06-04 13:00 hörsal 9, hus D, Stockholm
    Korobenko, Larysa
    Stockholm University, Faculty of Humanities, Department of Slavic and Baltic Studies, Finnish, Dutch, and German.
    Шведская коллекция славянских пергаменных фрагментов: Кодикологическое и палеографическое исследование2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This dissertation carries out a codicological and palaeographic investigation of Slavic parchment fragments taken from Russia to Sweden as war booty during a period of Swedish-Russian cultural interactions and military conflicts in the late 16th – early 17th centuries. The fragments in question were kept in Sweden until the beginning of the 19th century and mostly used as accounting binders. After 1809, some accounting records of Finnish territories (along with their parchment covers) were transferred from Sweden to Finland. Among them were accounting records with Slavic covers. In Finland, the parchment covers were removed from the accounting books and administrative documents that they had enclosed and sent to the University Library in Helsinki (now the National Library of Finland). In 1869, the Slavic fragments stored in Finland were donated to the Russian Academy of Sciences in St. Petersburg and then preserved in the Academy’s library (BAN, collection “Finliandskie otryvki”). Two Slavic fragments later came to England with George Stephens’ collection. Thus, the Slavic fragments are now held in archives, libraries and museums in four countries (Sweden, England, Finland and Russia). I use the designation The Swedish Collection of Slavic Parchment Fragments to refer to these four collections, once preserved in Sweden as part of a larger Swedish collection (the largest collection of medieval parchment fragments in Europe).

    All the parchment fragments belonging to the Swedish collection are undated, i.e. they have no inscriptions or additional information about the scribe, owner or patron, which would make it possible to immediately establish the time and place of their creation. This circumstance determined my choice of method for the analysis of the preserved fragments. They are studied in a comprehensive manner that combines codicological, palaeographic, historical and linguistic analysis. This has made it possible to pursue the study of the fragments in different directions, and to obtain the new specific and more general results presented in this dissertation.

    The palaeographic method of identifying scribes on the basis of their handwriting enabled me to connect different fragments with each other as well as with comparative manuscripts, and to determine their origins in the Mediaeval scriptoria of ancient Rus′: they were produced not only in Novgorod, but also in Pskov, Rostov and Moscow.

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    Шведская коллекция славянских пергаменных фрагментов: Кодикологическое и палеографическое исследование
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  • Public defence: 2024-06-05 10:00 Magnéli Hall, Kemiska övningslaboratoriet, Stockholm
    Morsali, Mohammad
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    Site-specific reactions of softwood kraft lignin for biobased vitrimers and reactive colloidal particles2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Lignin, a natural polyphenolic compound of wood, holds promise as a green alternative to fossil resources given the current environmental concerns. However, its complex structure and limited usability have impeded widespread use of lignin in biobased materials. This thesis is focused on employing a series of chemistries and techniques that facilitate lignin utilization in a variety of applications ranging from bulk materials to colloidal particles. Lignin-based vitrimers, developed by a one pot, catalyst-free click addition of poly(ethylene glycol) divinyl ether to softwood kraft lignin and formation of dynamic acetal exchange network showed excellent performance as recoverable adhesives, reaching lab shear strengths of 2.6 MPa and 6.0 MPa for wood and aluminum substrates, respectively. Stabilized lignin nanoparticles synthesized by hydrothermal crosslinking of hydroxymethylated lignin nanoparticles showed an excellent colloidal stability in organic solvents such as ethanol, acetone, dimethylformamide, and tetrahydrofuran, and aqueous media (3 < pH < 12). These stabilized lignin nanoparticles were subjected to direct surface modification in colloidal state to develop aminated pH-responsive particles. Stabilized lignin nanoparticles, preserving redox activity, showed a capacity in reducing silver ions, forming hybrid lignin-silver nanoparticles for applications such as hydrogen peroxide colloidal sensors. Interaction of silver ions and stabilized lignin nanoparticles contributed to the emergence of discrete patterns of silver in lignin nanoparticle embedded hydrogels. The location and distance of the discrete patterns can be modified by altering the particle size and concentration. Furthermore, redox activity of stabilized lignin nanoparticles, hydroxymethylated lignin nanoparticles and unmodified lignin nanoparticles with different particle sizes (90 nm, 150 nm, 640 nm) were studied in charge storage applications in organic poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) electrodes. Non-modified lignin nanoparticles with the diameter of 150 nm showed the best performance overall, with specific capacities of the electrode reaching 42.5 mAh/g at a current density of 1 A/g. These particles were also demonstrated in a Zinc-lignin battery prototype. To further explore and broaden the horizon of lignin applications, propargylated lignin nanoparticles demonstrated light-induced “click” reactions initiated thermally or by Cu (I) or energy-efficient light emitting diodes with 405 nm wavelength. These nanoparticles were further employed to demonstrate the light-triggered reactions with betulin azide in Pickering emulsions, showcasing the versatility of colloidal chemistry of lignin and opportunities for new applications.

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    Site-specific reactions of softwood kraft lignin for biobased vitrimers and reactive colloidal particles
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  • Public defence: 2024-06-05 10:00 sal FB42, AlbaNova universitetscentrum, Stockholm
    Viswanath, Gayathri
    Stockholm University, Faculty of Science, Department of Astronomy.
    A Window into the Cradle of Planets: Direct detection and characterisation of young sub-stellar objects using high-contrast tools2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Ever since we first laid eyes on the twinkling lights in the night sky, our species began its age-old quest to understand how we came into existence as a planet and what the future holds for it. Most of the traditional formation theories of planets were anchored on the examples drawn from our own solar system. With the surprising and emerging trends among the yet incomplete exoplanet demographics, we are at the wake of a rigorous revision of our theoretical understanding of how planets form and evolve. To form accurate theories however, it is necessary to base them on a planet population that spans the complete range of parameter space not only in terms of its physical properties like mass and orbital separation, but also with respect to the type of stars that host these planets and their age. In this regard, direct detection, whereby you measure photons coming from the planet, helps one get closer to the whole picture since the ideal target population for this technique are young, giant planets in wide orbits that are generally difficult to observe with other detection techniques. Over the last few years, the sensitivity reached by direct imaging observations has seen tremendous improvement owing to the use of high-contrast tools like coronagraphy and adaptive optics. The development of high-resolution spectrographs together with advanced post-processing techniques have recently, for the first time, enabled witnessing planets while in the process of being born, helping us understand how they grow by devouring material from the planetary nursery — a mechanism known as accretion. This is an exciting era for planetary science, with many ongoing as well as planned future surveys with both ground and space-based telescopes dedicated to unravelling the mysteries surrounding the origin of planets. 

    In this thesis, I provide an overview of direct detection as a tool to study sub-stellar objects – a categorisation that includes both planets and brown dwarfs, and whose blurred lines of distinction is a point of contention in astronomy today. I concentrate my discussion on two techniques, high-contrast imaging and high-resolution spectroscopy, both of which have proven significant in the race for planet detection and characterisation. Three scientific research works are carried out as a part of this thesis, using which I highlight the benefits of these techniques in constraining the physical properties of planets and brown dwarfs, as well as obtaining clues to their formation mechanism. In Paper I, I search for a Jupiter-like planet around a nearby Sun-like star that has long eluded imaging surveys, revealing its presence only via its influence on the parent star. I show how the brightness constraints at various separations and multiple wavelengths from the parent star help set a lower limit on the vaguely defined age of the system, in the absence of detection of the planet in our observations. In Paper II, I report the discovery of two low-mass companions to a massive, bright, young star, infer their orbital dynamics from multi-epoch imaging data, and constrain their physical properties using simultaneous low-resolution spectroscopy. In Paper III, I use a high-resolution spectrograph to observe for the first time, resolved Hydrogen and Helium emission lines from a young, isolated planetary-mass object in the midst of formation. Based on analysis of these line profiles, I obtain clues to the possible accretion mechanism at play in this nebulous cosmic phenomenon.

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  • Public defence: 2024-06-05 13:00 De Geersalen, Geovetenskapens hus
    Axelsson, Josefine
    Stockholm University, Faculty of Science, Department of Physical Geography.
    Interglacial climates in proxies and models: Utilizing sampled oxygen isotopes and model simulations to understand past Indian summer monsoon variability2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The study of Earth's climate system, including the mechanisms driving monsoon systems, is a key area of research within environmental sciences. Monsoons, vital for billions of people, are complex atmospheric phenomena influenced by various global factors, including orbital changes and natural climate variability. Among monsoon systems, the Indian summer Monsoon (ISM) is of particular interest due to its significant impact on the South Asian climate, agriculture, and water resources. Despite extensive study, comprehending the ISM's historical variability and its future implications remains a challenge. Utilizing natural archives like speleothems, along with stable water isotopes from precipitation and advanced climate model simulations, this thesis aims to decipher the ISM's responses to natural forcings across key interglacial periods—the Last Interglacial and the Holocene.

    Our findings indicate that the ISM's strength is critically influenced by slight variations in orbital configurations, leading to significant shifts in monsoon patterns. Our research also highlights the dual influence of local geographical features and distant atmospheric conditions on the ISM's annual variability. Most notably, we observed discrepancies between δ18O values obtained from isotope-enabled climate models and those derived from speleothems. This insight indicates that the models need refinement to accurately mirror the complexities observed in the proxy records and that the uncertainty parameter in speleothem records needs to be improved.

    The alignment between proxy and model data is crucial for a more accurate reconstruction of past climates and for enhancing the predictive capabilities of future monsoon behavior under changing climatic conditions. By advancing our knowledge of the ISM's past, we are better equipped to anticipate its future. To achieve that, this thesis stresses the importance of bridging the gap between proxy data insights and climate model simulations. This would not only enrich our historical climate knowledge but also inform future climate projections, highlighting the indispensable role of interdisciplinary research in climate science challenges.

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  • Public defence: 2024-06-05 13:00 Hörsal 2, Södra huset, hus A, Stockholm
    Duggan, Nora
    Stockholm University, Faculty of Humanities, Department of Linguistics.
    Deaf migrants in Swedish adult education: Language ideologies, repertoires, and translingual practices2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is concerned with language learning experiences of deaf migrants in Swedish adult education with a particular focus on how linguistic, social, and cultural factors influence their experiences. Additionally, the thesis critically questions the feasibility of ‘full integration’ for deaf migrants in Swedish society. The four studies comprising this thesis employ various sociolinguistic theoretical frameworks to investigate these complex issues.

    While it is common for migrants to face hurdles upon arrival in a new country, deaf migrants often encounter additional challenges. A notable contrast between deaf and hearing migrants in Sweden is that it is common for hearing migrants to learn Swedish so they will not need to use interpreters while deaf migrants learn Swedish and Swedish Sign Language so that they can use interpreters. This places significant pressure on deaf migrants, as not being able to learn Swedish Sign Language may restrict their access to essential services such as healthcare. Moreover, it is possible that deaf migrants have had limited access to language in their home environment prior to coming to Sweden. These disparities present formidable challenges not only for deaf migrants but also for education and public service providers. Given Sweden’s emphasis on the importance of language learning in term of integration, it is crucial to better understand deaf migrants’ language learning experiences and, in turn, how it affects their experiences of integration.

    This thesis explores deaf migrants’ language learning experiences and how these affect their opportunities for integration into Swedish society. Employing linguistic ethnography as an approach, the empirical data include video recordings from participant observations and semi-structured interviews conducted in four folk high schools (equivalent to non-formal adult education) across Sweden. Based on the analysis of these data, this compilation thesis comprises four studies: (i) an exploration of language ideologies constructed in the classrooms and their impact on deaf migrants’ language learning experiences, (ii) an examination of different translanguaging strategies used in the classrooms and the efficiency of these strategies, (iii) an investigation of the sociocultural factors that influence language use and language learning, and (iv) an examination of the effects of the Swedish bureaucratic system on deaf migrants’ integration experiences.

    These studies highlight the challenges associated with deaf migrants’ language learning that need to be considered before creating language policies that affect marginalised groups. This thesis offers new insights into how deaf migrants experience learning new languages and how their languaging challenges linguistic norms in Swedish society. Lastly, this thesis underscores the need for a transformative approach to language education that embraces different ways of languaging and places diversity and equity at the forefront.

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  • Public defence: 2024-06-07 10:00 lärosal 4, hus 1, Albano, Stockholm
    Theodosiadis, Eleftherios
    Stockholm University, Faculty of Science, Department of Mathematics.
    Geometry of multi-slit Loewner chains and semigroups of finite shift2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis deals with two topics in complex analysis that are related to families of Riemann maps that depend on some parameter function called the driving function of the family. One is Loewner theory and the other is the theory of semigroups of holomorphic self-maps of the unit disc. This thesis consists of four works, three of which lie in the intersection of the two theories and the other one refers solely on semigroups.

    In Paper I, we deal with the Loewner equation both in the unit disc (the radial  case) and in the upper half-plane (the chordal case). The solutions to these equations, which depend on the space and time variables, are called (radial or chordal) Loewner chains. Its main purpose is to present explicitly solutions to certain choices of driving functions and additionally visualize their geometry as time evolves. In particular, we deal with conformal maps with finitely many slits, for both cases. Thus, the aforementioned evolution involves the growth of multiple curves either in the unit disc or in the upper half-plane. Secondly, we discover the semigroup nature of these families, which we utilize in order to connect the radial with the chordal case through a Möbius transform, although in the general theory this is not always possible.

    The second paper is a continuation of Paper I, where we extend the study of the chordal Loewner chains of Paper I to chains with infinitely many slits. Again, we study the geometry of the chains as time evolves and we find the same geometric behaviour as in Paper I. However, this study is more complicated and requires a different approach that involves techniques from classical complex analysis and the use of the harmonic measure.

    In Paper III we are concentrated in a specific type of semigroups. We call those semigroups of finite shift. In the general theory of semigroups, several authors have studied the rate of convergence of a semigroup to the Denjoy-Wolff point, in terms of the Euclidean distance. In this direction, we also examine the rate of convergence for this case, in terms of the Euclidean distance, the hyperbolic distance and also in terms of the harmonic measure. 

    In Paper IV, we present some computational examples of Loewner chains. Some of them are related to those appearing in Papers I and II. We work similarly in the sense that we solve the Loewner equation for some certain driving functions. In addition, we have collected some Loewner chains that do not appear in the literature and we recover their driving functions. Our intention is to visualize these elementary examples in an effort to compare the geometry of the chains with their driving functions.

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  • Public defence: 2024-06-07 13:00 FB42, AlbaNova universitetscentrum, Stockholm
    Tan, Pueh Leng
    Stockholm University, Faculty of Science, Department of Physics.
    Solar Reflected Dark Matter with XENON1T and XENONnT: Searching for sub-GeV Dark Matter using liquid xenon Time Projection Chambers2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The XENONnT experiment is a low-background dual phase liquid xenon Time Projection Chamber (TPC) with 5.9 tonnes of instrumented liquid xenon. Improved liquid xenon purification and radon distillation system along with various background mitigation strategies brought the Electronic Recoil (ER) backgrounds down to an unprecedented low of (15.8 ± 1.3) events/(keV tonne years) below recoil energies of 30 keV.

    Exploring three different ER datasets spanning 10 to 140 keV collected using the XENON1T and XENONnT detector, a search for a signal of sub-GeV Dark Matter boosted by reflection off the sun is conducted. No excess is observed, and novel stringent upper limits on the Dark Matter-electron scattering cross section in the Dark Matter mass range between 5 keV and 9 MeV are reported.

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  • Public defence: 2024-06-10 10:00 hörsal 9, hus D, Stockholm
    Paues, Fredrik
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Essays on Housing Deregulation and Investment Behavior2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Welfare effects of deregulating the Swedish rental housing market

    The Swedish rental housing regulations have been rated the strictest among the OECD countries. In this chapter, I examine deregulatory reforms and how different redistributive schemes affect prices, inequality, and welfare. For this purpose, I build a static general equilibrium model with heterogeneous agents, which I calibrate to match the Swedish economy. I find that all households support a reform that allows households to freely trade rental contracts. Such a reform results in a welfare gain of 411 SEK per adult equivalent and year.

    How should rental housing deregulation be timed?

    I build on the first chapter and examine with what timing households would prefer that the rental housing market was deregulated. I develop a dynamic general equilibrium model of a small open economy. After calibrating the model to match salient features of the Swedish economy, I use it to test and evaluate four reforms that deregulate the rental market with different time profiles. I find that, in the long run, house prices and rents in the regulated housing stock increase by 267 and 25 percent, respectively, irrespective of the reform. In the unregulated housing stock, they fall by 19 and 6 percent, respectively. In the short run, nonhomeowner outsiders prefer reforms that remove regulations swiftly whereas homeowners and insiders prefer more gradual removals.

    The role of cognitive and noncognitive skills for investment behavior

    We analyze layman investment behavior in a mandatory defined contribution pension plan and find strong heterogeneity in behavior and performance outcomes. In the Swedish pension system reform of 2000, entrants in the year of the launch were 51 percentage points more likely to opt out from the default fund compared to those who entered one year later. Particularly likely to opt out were individuals with prior investment experience and high noncognitive skills. Cognitive skills, on the other hand, fostered activity in terms of reallocation between funds. As a consequence, the return loss associated with a one-standard deviation increase in noncognitive skills is estimated to 11 basis points per year while cognitive skills are unrelated to returns in the pension plan. We argue that the peculiar relationship between noncognitive skills and returns stems from the circumstances at the time of the launch—only pension investors who entered the plan in 2000 suffered a return loss associated with noncognitive skills—and that the correlation between noncognitive skills and opting out from the default fund at the launch of the reform is likely a result of the intense information and advertising campaigns that took place.

    Identity capital and wealth accumulation

    We develop a theory of identity capital. Identity is built up around a "life project" that can take many forms and in which individuals invest time and/or money; identity capital is a stock measure capturing these investments. In this paper, we focus on the life project of building a firm and its possible relevance for (1) the high propensity to save of rich entrepreneurs and (2) the rise of risky portfolio shares in wealth. To this end, we introduce identity capital into a dynamic consumption-savings model with uninsurable idiosyncratic risk. The key model feature is a utility asymmetry: We assume that decumulating, or losing, identity leads to a utility loss, while building it up renders no utility gain. We find that identity management makes individuals reluctant to downsize when the firm's financial prospects are weak as well as to invest when they are strong.  The model also implies that, at least in parts of the wealth-identity space, the risky portfolio share increases in wealth, a result that is hard to obtain in standard models with constant relative risk aversion.

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  • Public defence: 2024-06-10 13:00 Högbomsalen, Stockholm
    Nair, Hari
    Stockholm University, Faculty of Science, Department of Environmental Science.
    Absorption enhancement of black carbon aerosols and the aerosol-induced masking effect on warming over South Asia2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis examines the effects of black carbon (BC) and other aerosols on the regional climate, focusing on their climate-relevant optical properties and implications for radiative effects. We focus on South Asia, home to one-third of the worldwide population. The abrupt societal changes during the COVID-19 pandemic led to an unprecedented reduction in anthropogenic emissions and provided a unique opportunity to study the impact of aerosol demasking on global warming. The thesis revolves around insights obtained from three atmospheric receptor observatories intercepting the outflow from South Asia, complemented by remote sensing data and aerosol modeling. These are:  Bangladesh Climate Observatory at Bhola (BCOB), positioned at the exit of the highly polluted Indo-Gangetic Plain (IGP), Maldives Climate Observatory at Hanimaadhoo (MCOH) in the Northern Indian Ocean, and Maldives Climate Observatory at Gan (MCOG) near the equator in the Indian Ocean. These observatories hence facilitate the measurements of aerosol properties from source regions to distant receptor environments and provide a comprehensive framework for assessing BC's regional climate impacts.

    The thesis offers insights into the changes in the sources of BC and the resultant climatic impact. The thesis quantifies the changes in the regional aerosol properties resulting from reduced anthropogenic emissions during the COVID-19 pandemic societal shutdown. The study reveals a substantial decrease in atmospheric aerosol loading, resulting in a reduction of the aerosol forcing roughly three-fourths of the magnitude of CO2-induced radiative forcing at the top of the atmosphere and a ~7% increase in surface-reaching solar radiation. This work also demonstrates a notable shift in relative contribution of BC sources at BCOB during the COVID period: fossil fuel contributions decreased from 49% to 35%, while C3 biomass burning increased from 31% to 55%, with C4 biomass remaining a minor source. Similarly, for MCOH, reflecting the outflow from the greater South Asian subcontinent, the contribution from fossil combustion decreased while C3 combustion increased.

    Further, the thesis explores the optical properties of BC, coating effects, and changes in mass absorption cross section (MAC) during long-range transport. The study shows a uniform MAC enhancement from water-soluble coatings of 1.6±0.5 across sites BCOB, MCOH and MCOG. However, the BC MAC increased by 80% in two separate studies from the IGP outflow at BCOB to the Indian Ocean receptor stations, suggesting a common underlying phenomenon.  This mechanism is likely linked to scavenging fractionation occurring during the long-range transport of BC, which selectively filters out larger, lower BC MAC particles. This results in a residual population of finer, hydrophobic BC particles characterized by a notably higher MAC678 at the receptor observatories in Northern Indian Ocean. Additionally, throughout the transport from the BCOB to the MCOH, BC particles undergo a transformation, becoming more absorbent—akin to becoming "darker." This transformation is facilitated by the photochemical bleaching of organic carbon (OC) and in-cloud processes, which further contribute to the increase in BC- BC-MAC678. On the other hand, BrC-MAC decreased due to photochemical bleaching.

    The findings of this thesis, based on observations, enhance our understanding of the constantly changing optical and radiative impact of human-made aerosols in the highly significant South Asian emission region. This, in turn, enables better descriptions of the evolving aerosol characteristics in climate models and offers guidance for informed policy-making and the development of effective climate mitigation strategies.

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  • Public defence: 2024-06-10 14:00 lärosal 4, hus 1, Albano, Stockholm
    Kuijper, Josefien
    Stockholm University, Faculty of Science, Department of Mathematics.
    It's hip to be square: Quadrilateral diagrams in geometry and K-theory2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis consists of four papers, which all contain a certain amount of squares. In Paper I, we study compactly supported cohomology theories of varieties. These can be seen as functors with a nice descent property, out of a category whose objects are varieties, and whose morphisms are spans that consist of an open immersion and a proper map. Using the theory of cd-structures, which are sets of commutative squares that generate a topology, we show that a compactly supported cohomology theory can be uniquely extended from its restriction to smooth and complete varieties. 

    In Paper II, we continue the study of cd-structures. If a morphism f between sites satisfies the conditions of the comparison lemma, then it induces an equivalence between the associated categories of (hyper)sheaves. If f is strong symmetric monoidal and the topologies in question are generated by sufficiently nice cd-structures, then we show that f also induces an equivalence between the associated categories of symmetric monoidal hypersheaves. We use this to prove a variant of the main result of Paper I for symmetric monoidal hypersheaves.

    The highest degree of square-ness is reached in Paper III. Here, commutative squares are used to build K-theory spectra, most notably for the category of varieties. We reuse some of the square-y arguments from Paper I to show that the K-theory spectrum of the category of varieties is equivalent to the K-theory spectrum of the category of complete varieties. Moreover, exploiting the square-ness of the category of compactly supported cohomology theories that is demonstrated in Paper I, we can construct a new derived motivic measure. Paper III is joint with Jonathan Campbell, Mona Merling and Inna Zakharevich.

    In Paper IV, we build on the result of Paper I, and its variation proven in Paper II, to obtain a result about functors that encode six-functor formalisms. Squares show up again, not only in the form of cd-structures, but also in the form of adjointable squares, which play an important role in extending a six-functor formalism from the domain of complete varieties to all varieties.

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  • Public defence: 2024-06-11 10:00 hörsal 9, hus D, Stockholm
    Hochmuth, Philipp
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Essays on Hours Worked and Cost-of-Living Inequality2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Declining Hours Worked Among Entrepreneurs

    In this paper, I show that over the past 35 years, hours worked by entrepreneurs have fallen substantially: by five hours per week more than for workers. This decline accounts for the bulk of the fall in total hours worked and is present in all available subgroups (gender, age, education, number of children, occupation, and industry). It is robust to adjusting for compositional effects and occurs without noticeable changes in the relative hourly income of entrepreneurs. The decline originates from the top of the hours distribution: the share of entrepreneurs working more than 45 hours has dropped significantly. I interpret these facts using a Roy model of occupational choice, augmented with an intensive labor supply margin. The model allows the marginal return of working an additional hour to depend on the level of hours. I estimate the model at two points in time and find that a fall in the relative marginal return at higher hours worked is key for explaining the drop in hours and the drop in the share of entrepreneurs. I show that changes in the market structure of the goods or services that entrepreneurs sell can account for this.

     A Nonhomothetic Price Index and Cost-of-Living Inequality

    We derive a nonhomothetic generalization of all superlative price indices and document cost-of-living inequality in the United States. When necessities and luxuries are separable in the expenditure function, this generalization eliminates the need to estimate a complete demand model. Using CEX-CPI data from 1995 to 2020, we find no differences in average inflation rates across the expenditure distribution, but 2.5 times higher inflation volatility for the bottom decile than the top decile, stemming from a larger exposure to food, gasoline, and utilities. Our analysis challenges inequality measurements using group-specific homothetic price indices and suggests an income-effect bias in these estimations.

    A Distributional PCE Price Index From Aggregate Data

    This paper proposes a method to measure individual and aggregate changes in the cost of living when consumer behavior is nonhomothetic and microdata on consumption expenditures are not available. Aggregate prices and expenditure shares together with a single cross-sectional distribution of expenditures are sufficient to create a distribution of nonhomothetic cost-of-living indices with this approach. The cost-of-living indices derive from PIGL preferences, generalize the Törnqvist price index, and only contain one unknown parameter. Because PIGL preferences aggregate consistently, this parameter can be identified from aggregate data. Using US Personal Consumption Expenditure (PCE) data, we apply the method to obtain a nonhomothetic PCE price index covering 71 product groups for the period 1959 to 2023. This index reveals a 0.39 percentage point gap in average annual inflation rates between the poorest and richest ten percent since 1959 and a 1.9 percentage point gap throughout 2022, thus suggesting that poorer households are hit harder both in the long run and in the recent inflation surge.

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  • Public defence: 2024-06-11 10:00 Aula Magna, Spelbomskan, Stockholm
    Garbelli, Marta
    Stockholm University, Faculty of Humanities, Department of Romance Studies and Classics.
    La microsintassi degli antichi volgari settentrionali: Articoli e pronomi personali nella prosa lombarda e veneta nei secoli XIII-XV2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis investigates the microsyntax of articles and personal pronouns in the medieval varieties of Lombardy and Veneto (13th–15th century). The study combines functionalism and grammaticalization theories with the principles of pragmatics and textual linguistics. The investigation draws upon a corpus of 47 texts selected to ensure representativeness across various diaphasic and diastratic varieties.

    The emergence of the article was analyzed based on syntactic, pragmatic, and semantic constraints. The analysis shows that syntactic instances exhibiting stronger diachronic resistance to the grammaticalization of the article are prepositional phrases, enumerations, and vocative phrases. Concerning pragmatic constraints, the definite article is generally required in the presence of universally known and unique referents as well as with inalienable possession. With respect to semantic constraints, there is greater fluctuation in the alternation between zero article and the definite article. The semantics of special noun classes (namely proper names, kinship terms, and abstract nouns) exerts greater resistance to the grammaticalization of the determiner. Overall, by the 14th century  in both Lombard and Venetan varieties, the definite article exhibits an advanced functional stage along the cline of grammaticalization. With respect to the indefinite article, uno is fully grammaticalized as a marker of specific indefiniteness while still competing with other constructions for marking non-specific indefinite referents. Moreover, the analysis attests to the early instances of partitive nominal constructions and partitive articles.

    Regarding the personal subject pronouns, their microsyntax was analyzed with respect to three interdependent phenomena characterized by complex processes of polymorphism, polyfunctionality, and reorganization of syntactic systems. On the expression of pronominal subjects (PS), the quantitative analysis highlights that the rate of PS expression is strongly dependent on the type of proposition, namely main, coordinate, and subordinate. Notably, the PS is generally expressed in main clauses and subordinate clauses, notwithstanding the presence of functional restrictions. This indicates a system where the expression of PS is typically obligatory in both clauses, conflicting with the so-called “asymmetric pro-drop” hypothesis. The analysis shows that the emergence of a new tonic paradigm of PS, developed from the oblique pronouns, is associated with special syntactic and pragmatic conditions. However, from the mid-14th century onward, the new tonic forms appear more frequently in the canonical subject position, signaling the rise of a new paradigm. This phenomenon coincides with the parallel emergence of subject clitics. Based on four syntactic criteria, the evidence hints at the development of a clitic subject paradigm exhibiting characteristics of a classic grammaticalization process such as weakening and cliticization.

    All in all, this thesis underscores the complex linguistic landscape of medieval Italy, and argues that the evolution of articles and personal pronouns in these substandard varieties aligns with the predictions from grammaticalization theories, providing insights into the dynamics of linguistic change.

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  • Public defence: 2024-06-11 14:00 FB52, AlbaNova universitetscentrum, Stockholm
    Dachlythra, Konstantina
    Stockholm University, Faculty of Science, Department of Physics.
    Beam Prepared: Modeling optical systematics for current- and next-generation CMB experiments2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The polarization of the Cosmic Microwave Background (CMB) is at the center of attention of the cosmological community, as the observable possibly offers a view of primordial gravitational waves. A signature from an early-universe gravitational wave background would be imprinted on the parity-odd pattern of the CMB polarization, namely the B-modes. Achieving a non-zero primordial B-mode detection would serve as indirect evidence of the current most favorable scenario describing the initial perturbations of the universe, referred to as cosmic inflation. Several current- and next-generation telescopes are targetting high-accuracy measurements of the polarized microwave sky, with a particular emphasis on probing the inflationary paradigm. This effort faces two key challenges. The first is the impact of the galactic contaminants on the cosmological signal, which may be tackled by telescopes with increased frequency and sky coverage. The second concern refers to systematic errors arising from the instrument itself, highlighting the necessity of establishing a robust framework for their modeling. This thesis focuses on the modeling of a leading category of systematics that is associated with the telescope’s optics in the context of CMB analysis. A part of the thesis discusses the impact that combining non-ideal beams with a specific type of realistic polarization modulators, namely Half-Wave-Plates (HWPs), has on the reconstructed CMB B-mode spectra of a simulated satellite experiment. The rest of the analysis refers to the Simons Observatory (SO) Small Aperture Telescopes (SATs) that are currently being deployed from the Atacama Desert in Chile. Specifically, I first assess our expected beam calibration capabilities during science observations of the SO SATs in terms of the telescope’s scientific objective. I then expand on the calibration strategy optimization and pipeline infrastructure I developed for the commissioning phase of the first deployed SAT. This study aimed to assess the telescope’s anticipated pointing and beam reconstruction accuracy during its initial observations. Finally, I investigate how natural variations in beam patterns across the SO observing frequency bands influence the large-scale B-mode spectra of the SATs. 

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  • Public defence: 2024-06-12 10:00 sal 110 (Aula/Hörsal), Frescati backe, Stockholm
    Novosel, Ylva
    Stockholm University, Faculty of Social Sciences, Department of Child and Youth Studies.
    Transspråkandets villkor i en supermångfaldig förskola: En konstruktivistisk grundad teori2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The aim of the thesis is to examine how preschool children’s translanguaging is performed, and the conditions that enable or limit translanguaging in preschool. Constructivist Grounded Theory (Charmaz 2014a) has been used to code collected data from a superdiverse preschool in a structurally disadvantaged suburb in Sweden, and to generate a provisional theoretical model of how to understand the conditions for translanguaging in this preschool. The following research questions have been posed: How is translanguaging performed in a superdiverse preschool? What are the conditions that enable or limit translanguaging in this preschool? How might a theoretical model on the performances and conditions for translanguaging, based on data from this superdiverse preschool, be constructed as a result of a constructivist grounded theory? The data were gathered in an ethnographic study, where approximately 90 percent of the children were multilingual. Seven multilingual children aged 1 to 5 years were shadowed during an intense 12-week period, during their first semester at preschool; initially doing fieldnotes, succeeded by six weeks of video-recordings. The children had different family languages (i.e. mother tongue) and were all emerging bilinguals, and thus new to the Swedish language. In line with definitions of translanguaging, I have coded the data from a multimodal view of language. This means observing body language, facial expressions, gaze, sounds, and the use of aesthetic ways of expressing yourself while drawing, moving your body, etc. as a part of what the Swedish preschool curriculum calls aesthetic expressions.  

    The results show that children translanguage by using their entire repertoire of verbal and non-verbal communication. Younger (1–3-year-old) children’s multimodal repertoire is more enhanced and supported by adults and other children. Older children (3–5-year-old) are expected to, but also more likely to use verbal language (Swedish, English or their family language). However, they are also often misunderstood, due to expectations when the verbal language is failing them. The study shows that translanguaging is conditioned by a complex mix of space-time and concrete-abstract dependent factors. These factors are: the didactic situation of play, care or teaching, material artefacts in environment, and notions, expectations and reception expressed by educators and other children. Especially strong are the expectations tied to the child’s age and its prior experiences of expressing itself verbally, bodily or in other ways. The results suggest that the openness in attitude, reception, response and expectations shown by adults and other children towards the youngest children while translanguaging, would greatly benefit older children as well. The study concludes that more knowledge about translanguaging in its wider definition, which also includes working with the possibilities afforded by aesthetic expressions, is beneficial for all children to enhance their communication, language development and multicultural identity-formation in accordance with the stipulated aims of the preschool curriculum. 

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  • Public defence: 2024-06-12 10:00 Hörsal 9, Hus D, Stockholm
    Hinkelmann, Stefan
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    On the Macroeconomics of the Energy Transition2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Climate Policies and Input Substitution over Time

    This paper investigates quantitatively how the impact of climate policies such as a carbon tax differs over the short and long run in the macroeconomy. We document limited possibilities to switch from fossil fuels to green alternatives over short time horizons. Over more extended periods, however, this substitutability increases significantly. The same pattern holds for aggregate energy in production. We then build a quantitative growth model that accounts for these patterns through a technology-choice channel. We find that, in order to achieve similar long-run emission targets, carbon taxes should be increased by about 10% permanently compared to models that focus on the long run only.

    Electrification of U.S. Aggregate Production: Theory and Evidence

    In this paper, I scrutinize the process of electrification, defined as an increase in the share of electricity in the energy bundle. I first document trends and facts regarding the use of fossil fuels and electricity as end-use energy types in production in the U.S. I provide evidence that these two energy types are strong complements in the short- but more substitutable in the long run. In particular, I estimate the short-run elasticity of substitution between these two energy inputs to be 0.06 and argue for a Cobb-Douglas relationship and, thus, a unitary elasticity of substitution in the long run. I then build a model that can quantitatively reproduce these facts through a directed technological change mechanism. Crucially, the main driver of electrification is the relative improvement of fossil fuel use efficiency vis-à-vis electricity's.

    (Be-)Coming Clean: A Model of the U.S. Energy Transition

    This paper develops a quantitative framework of the energy transition and shows how the decarbonization of the economy hinges on three main mechanisms endogenous to the model: (i) developments in energy efficiency determining energy use in a growing economy; (ii) electrification of the production process driven by directed technical change; and (iii) capacity building for green electricity production. I then use the model to evaluate a net zero by 2050-policy vis-à-vis business as usual. I find that the energy transition happens in a laissez-faire scenario but has to be sped up if the policy target is to be fulfilled. In particular, I find that the required carbon tax is initially around $250 per ton CO2, and output and consumption growth are transitionally 0.2-0.3 percentage points lower under environmental policy.

    Green Subsidies, the Energy Transition, and Implications of the Inflation Reduction Act

    This paper studies the implications of green subsidies on the economy and the energy transition. I include a technology and a learning-by-doing (LBD) externality in Chapter 3’s framework. The internalization of these inefficiencies requires green subsidies, which have important implications for the energy transition. In particular, fossil fuel use in the economy will reduce by 38% by the end of the 2060s compared to laissez-faire. Additionally, the two externalities interact. Internalizing the LBD mechanism reduces the technology externality, while internalizing the technology shift exacerbates the implications of unaccounted-for LBD. Investigating the IRA shows that it is leveraging the right externality with an imperfect instrument: ITCs do not perfectly internalize the LBD externality and lead to fossil fuel use rebounding after their expiration.

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  • Public defence: 2024-06-12 13:00 ALB Auditorium 4, 2nd floor, house 2, Campus Albano, Stockholm
    Zhang, Dongni
    Stockholm University, Faculty of Science, Department of Mathematics.
    Stochastic epidemic models with contact tracing2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The COVID-19 pandemic has significantly heightened research interest in infectious disease modelling. Specifically, the pandemic has underscored the critical role of epidemic models in understanding and predicting epidemic dynamics as well as evaluating the impact of public health interventions. This thesis delves into stochastic epidemic modelling, concentrating especially on the effectiveness of contact tracing to prevent large outbreaks.

    In Paper I, we consider a Markovian SIR epidemic model in a homogeneous community with a rate of diagnosis (testing). This model is then incorporated with traditional manual contact tracing: once an infectious individual tests positive, it is immediately isolated. Each of its contacts is traced and tested independently with some fixed probability. Using large population approximations, we analyzed the early stage of the epidemic when the process of “to-be-traced components” behaves like a branching process. Based on these approximations, the analytic expressions for the reproduction numbers (for the components and individuals), the probability of a major outbreak, and the final fraction getting infected are derived and numerically evaluated. For the main stage of the epidemic, the process of to-be-traced components converges to a deterministic process (defined by a system of differential equations). Our numerical results suggest that the manual tracing probability is more effective in reducing the reproduction number than the testing fraction.

    Paper II concerns a similar epidemic model as in Paper I but focuses on digital contact tracing (based on a contact tracing app) and a hybrid approach combining both manual and digital tracing. We assume manual as well as digital contact tracing occurs instantaneously and recursively for mathematical tractability. This model is then analyzed using a two-type branching process relying on a large community, where one type of “individuals” are “app-using components” and the other is non-app-users. Further, we investigate the combined preventive effect of two tracing methods. This combined model is analyzed by a different two-type branching process, with both types being the “to-be-traced components” but starting with different “roots”. The corresponding reproduction numbers R are derived. It is proven that the critical fraction of app-users for which digital contact tracing to R=1 is larger than the critical manual reporting probability to reach R=1.

    Paper III presents an SEIR epidemic model allowing for network and random contacts, incorporating manual and digital (app-based) contact tracing. Manual tracing is only allowed to happen on the network and has random tracing delays. In contrast, instantaneous digital tracing occurs among network and random contacts (both need to be app-users). Both manual and digital tracing are assumed to be forward only and non-iterative. We show that the initial phase of the epidemic with both manual and/or digital tracing can be approximated by different multi-type branching processes, leading to the derivation of three respective reproduction numbers. This paper sets a lower bound on the effectiveness of contact tracing through its conservative assumptions, while Paper II offers an upper bound by presenting an optimistic scenario. The actual effectiveness of contact tracing in real-world situations is expected to fall somewhere in between.

    Paper IV explores an epidemic model with sideward contact tracing. Individuals are involved in mixing events that occur at some rate. Infection is driven by interaction with at least one infective at the mixing event rather than pairwise interaction outlined in Papers I, II and III. Once an infective is diagnosed, each individual who got infected at the same event as the diagnosed individual is traced with a certain probability. Assuming few initial infectives within a large population, the initial stage of the epidemic is approximated by a limiting process where individuals can be traced by their siblings (individuals who become infected at the same event), thus creating dependencies. Treating sibling groups as macro-individuals allows for a macro branching process interpretation, from which we derive the reproduction number. Finally, we present some numerical results showing how the reproduction number varies with the size of the mixing event, the fraction of diagnosis and the tracing probability.

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  • Public defence: 2024-06-12 13:00 hörsal 3, södra huset B, Stockholm
    Joosten, Sjors
    Stockholm University, Faculty of Social Sciences, Department of Sociology.
    100% Swedish: Working for recognition through Hip-Hop from the suburbs of Stockholm2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This dissertation examines the role of hip-hop in shaping identity, immigrant integration, and social belonging in the Swedish context. It discusses how Swedish hip-hop artists with immigrant backgrounds and from segregated suburbs use their art to translate personal narratives, communicate social realities, and imagine alternative conceptions of Swedishness. The research draws upon Civil Sphere Theory (Alexander, 2006) and Recognition Theory (Lamont, 2018, 2023), which focus on symbolic boundaries that are in play in the conception of who “we” are as a society and associated processes of inclusion, belonging, and recognition. The study investigates how hip-hop assists immigrant-Swedish artists to articulate their experiences, construct identities, and navigate processes of integration and instances of exclusion. By describing the impact of the work of hip-hop artists and other key actors in the hip-hop scene, the dissertation considers the implications of hip-hop for immigrant incorporation, social recognition, and belonging within Swedish society. 

    The analysis is based on qualitative data, including interviews with immigrant-Swedish hip-hop artists and other stakeholders of the hip-hop scene related to the suburbs of Stockholm, observations of significant places and performances in the Stockholm hip-hop scene, analysis of lyrics, and interpretation of secondary sources like media coverage. Through the analysis of this data, the dissertation uncovers how hip-hop artists challenge territorial stigmatization, work against racialization and discrimination, and strive for a greater appreciation for cultural hybridity and the multicultural reality of Sweden. 

    The findings provide a nuanced portrait of hip-hop as a site of both empowerment and struggle for immigrant-Swedish individuals and communities. While hip-hop offers a platform for artistic expression, economic advancement, and agency, it also confronts tensions between commercial success and social marginalization that can reinforce stigmatizing stereotypes and social exclusion or support recognition and integration. As hip-hop becomes more mainstream, artists appear on public TV shows, perform on national stages, and enter the finer rooms of the cultural landscape. Hip-hop from the suburbs has become more present and widespread. However, it continues to be seen as produced in symbolically excluded spaces by immigrant-others. A substantial factor in this is the disproportionate attention to gangster-rap, which emphasizes criminality and exclusion, undermining other hip-hop artists that try to convey messages that facilitate belonging and recognition. 

    The dissertation clarifies symbolic boundaries between the construction of a dominant and conventional 'lagom' Sweden and an immigrant-Swedish multicultural suburban 'orten' Sweden, and argues that artists often work towards new forms of belonging and recognition, potentially redefining these symbolic boundaries and contributing to immigrant incorporation on a larger scale. But this depends significantly on the artists’ ability to balance a mastery of knowing how to approach the wider audience through hip-hop and change-making in sharing messages to discuss redefining symbolic boundaries in favor of a more inclusive society. It can be concluded that Swedish hip-hop does not only work on an individual level for creating alternative forms of identities and routes to belonging but also adds to a social critique of how symbolic boundaries are drawn and can work towards imagining a multicultural and inclusive Sweden that is both 'lagom' and 'orten,' thus 100% Swedish. 

    Ultimately, this dissertation contributes to research on immigrant incorporation, belonging, and recognition through the arts and music – specifically popular culture – and demonstrates the value of hip-hop for research on immigrant inclusion and belonging. This dissertation underscores the transformative potential of hip-hop as a catalyst for broader societal change, reshaping conceptions of Swedish identity and challenging existing boundaries of belonging. By identifying translation, communication, and imagination as the key actions of hip-hop artists and other cultural agents, the study contributes to theoretical advancements bridging Civil Sphere Theory with Recognition Theory. Contributing to the sociology of immigrant incorporation by clarifying the interplay between symbolic boundaries and music, the research offers new insights into how immigrant-Swedish artists and their communities navigate processes of integration and belonging.

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  • Public defence: 2024-06-13 13:00 hörsal 9, hus D, Stockholm
    Lindström, Tobias
    Stockholm University, Faculty of Humanities, Department of Archaeology and Classical Studies.
    Människor, djur och varelser i miniatyr: Flerartliga förbindelser i den gropkeramiska kulturen2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis attempts to understand the relationships between humans and animals in the Middle Neolithic (c. 3300-2300 BC) Pitted Ware culture (PWC) in Eastern Sweden and the Baltic islands of Gotland and Åland. This is accomplished through an examination of the zoomorphic and anthropomorphic clay figurines that have been found on many PWC sites in the study area, and to a lesser extent also the use and deposition of animal bones. The archaeological material is approached using a theoretical framework that draws upon hunter-gatherer relational ontologies and new materialisms.

    Comparisons between the anthropomorphic figurines and the zoomorphic figurines reveal clear morphological differences that are not attributable to the bodily differences between humans and animals. Instead, it is argued that they indicate contrasts in human-animal and human-human interactions respectively, and that they also had bearing on the engagements and relationships between humans and figurines. The chronological and geographical distribution of figurines further suggest that the anthropomorphic figurines represent a younger, more localized development in the PWC figurine tradition commencing around 2900 BC. This could possibly also be understood against the backdrop of a general ‘anthropomorphization’ in Europe during the 3rd millennium BC and the wider societal changes in northern Europe. 

    In contrast to the figurines, which are uncommon in burials and deposits, animal bones have obviously been selectively deposited at many PWC sites. Unmodified animal bones found in certain features, deposits and burials reveal interesting patterns, where bones from the limbs and heads are overrepresented. The parts chosen can be described as those that relate to the perception and movements of the various animals deposited. The treatment of the animal bones might be understood as a way of dealing with a persistent animal awareness that resided in the bones and needed to be controlled.

    Zoomorphic figurines and animal bones thus seem to have had complementary uses at the PWC sites and configured human-animal relations in different ways. The figurines might have been involved in influencing prospective prey animals, while the deposition of animal bones was a means of handling animals that had been successfully killed. 

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  • Public defence: 2024-06-13 13:00 hörsal 8, hus D, Stockholm
    Sen, Sreyashi
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Essays on Markets and Institutions in Developing Countries2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Labour Regulations and Industrial Performance: Evidence from India

    This paper investigates the impact of recent state level reforms passed over the period 2003 to 2016 to a central law on industrial relations, the Industrial Disputes Act of 1947, on plant outcomes in the formal manufacturing sector in India. Exploiting variation in the timing of the state level reforms, I use a stacked event study design that compares treated plants to similar control plants in untreated states to estimate the average effect of state level reforms classified as pro-worker or pro-employer. I find that labour reforms that are pro-employer significantly raise plant output, wage bill and the average earnings of workers, while pro-worker reforms are negatively related to average worker earnings but have no other meaningful effects on plant performance. I also find heterogeneity in estimated treatment effects, with place based labour reforms targeting specific industrial locales having higher effects on average compared to other types of labour reforms.

    The Impact of Size-Dependent Labour Laws on the Allocation of Resources in India

    I investigate the effect of job security provisions in India that imposed regulatory requirements on plants above a certain size threshold. Using data on plants in the registered manufacturing sector in India over the period 1998 to 2018, I first test for discontinuities in the size distribution of plants at the regulatory threshold of 100 workers. I do not find evidence of significant discontinuities in the plant size distribution at 100 workers. I then use a sharp regression discontinuity design to examine if there are systematic differences in plant outcomes at the regulatory threshold. I provide suggestive evidence that regulatory costs lead to a decline of 6.7% in plant output.

    A Quantitative Study of Poverty Traps

    This paper undertakes a quantitative exploration of how initial conditions matter for long run economic outcomes when there are capital market imperfections, using a model of occupational choice with financial frictions. The model exhibits both poverty traps at the level of the individual, as well as at the aggregate level. At the level of the individual, I find multiple steady states for similar individuals starting out with different wealth levels, with differences in wealth and consumption that persist over time. Aggregate poverty traps arise in this model due to general equilibrium effects of wages adjusting to individual occupational choices. I numerically show certain initial conditions, in terms of the distribution of wealth and aggregate capital, that determine whether economies converge to a high wage equilibrium or stay trapped in poverty at a low wage equilibrium.

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  • Public defence: 2024-06-13 14:00 Lärosal 4, hus 1, Albano, Stockholm
    Stoll, Robin
    Stockholm University, Faculty of Science, Department of Mathematics.
    Relative self-equivalences and graph complexes2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis consists of three papers.

    In Paper I, we identify the cohomology of the stable classifying space of homotopy automorphisms (relative to an embedded disk) of connected sums of Sk × Sl, where 3 ≤ k < l ≤ 2k - 2. We express the result in terms of Lie graph complex homology.

    In Paper II, we construct a rational model for the classifying space BautA(X) of homotopy automorphisms of a simply connected finite CW-complex X relative to a simply connected subcomplex A. Using this model, we provide a purely algebraic description of the cohomology of this classifying space. This constitutes an important input for the results of Paper I.

    In Paper III, we show that modular operads are equivalent to modules over a certain simple properad which we call the Brauer properad. Furthermore we show that the Feynman transform corresponds to the cobar construction for modules of this kind. To make this precise, we extend the machinery of the bar and cobar constructions relative to a twisting morphism to modules over a general properad. As an application, we provide the foundations of a Koszul duality theory for modular operads.

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  • Public defence: 2024-06-14 09:00 hörsal 9, hus D, Södra Husen, Stockholm
    Linnros, Evelina
    Stockholm University, Faculty of Social Sciences, Department of Economics.
    Essays on Fertility and Health2024Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Infertility Risk and Child Marriage

    The high infertility rates observed in some developing countries may have broad societal impacts, for example by people marrying and having children at a young age to increase their chances of reaching their fertility target. I study the link between infertility risk and marriage timing using data from Madagascar. Specifically, I focus on how infertility risk affects the probability of child marriage, a practice associated with adverse outcomes for young brides and their children. I use spatial variation in exposure to the parasite schistosomiasis. The empirical strategy compares two strains of this parasite, similar in their transmission mechanisms and health impacts, except that one of the two strains causes infertility. In my data, exposure to this strain increases the probability that a woman is infertile by 40%. I find that exposure to the infertility-causing strain increases the probability of child marriage and early fertility by 22%.

    Maternal Health and Labor Market Outcomes

    We study how severe injuries related to childbirth affect mothers' labor market outcomes. 1 in 20 first-time mothers who have a vaginal delivery suffer a severe birth tear, which can have long-lasting adverse impacts on their health and quality of life. Using a difference-in-differences design with a matched control group, we find that severe birth tears lead to a 6% higher earnings loss in the first five years after childbirth compared to the control group. The effect is larger for mothers from low SES backgrounds, while high SES mothers are found to seek more healthcare following their injury.

    Alcohol Availability, Prenatal Conditions and Midlife Mental Health

     We examine the long-term mental health effects of an 8.5-month policy experiment that led to a sharp and unexpected increase in alcohol availability, focusing on individuals exposed to the policy in utero. We use administrative healthcare and drug prescription records to identify individuals who have received treatment for a mental health disorder. Prenatal exposure to the policy had a large and persistent effect on mental health: the exposed cohort is 16% more likely to be treated for a mental disorder in midlife. The effect is largest for those exposed from the second trimester and is only partly explained by the lower earnings observed among exposed individuals.

    The Value of Monitoring for Disaster Prevention: The Desert Locust

    Monitoring systems are meant to detect early signs of potentially disastrous outbreaks of diseases and pests, in time for preventative action. These monitoring systems are costly, and identifying their economic value requires estimating damages from outbreaks in empirical settings where monitoring is neither uniform nor exogenous. We estimate the value of monitoring systems for desert locusts, known to devour entire agricultural fields. We leverage conflict and weather events in breeding areas to detect the effects of monitoring interruptions on swarm outbreaks. We then reconstruct the spatial patterns of locust migrations to propagate these effects on swarm outbreaks beyond breeding areas. Finally, we show that in-utero exposure to a swarm increases the probability of stunting by 16%. These estimates allow us to quantify the effects of a change in monitoring efforts on subsequent locust swarms and on human health.

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  • Public defence: 2024-06-14 09:30 Lärosal 4, hus 1, Albano, Stockholm
    Hainaut, Louis
    Stockholm University, Faculty of Science, Department of Mathematics.
    Configuration spaces on a bouquet of spheres and related moduli spaces2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis is a compilation of four papers, revolving primarily around the cohomology of certain configuration spaces and moduli spaces. 

    Paper I studies the Euler characteristic of configuration spaces over a large family of base spaces X, with any constructible complex of sheaves as coefficients. This paper generalizes a previous formula of Gal, which applies to the restricted case when X is a finite simplicial complex.

    Paper II, written jointly with Nir Gadish, studies configuration spaces on a bouquet of spheres X via their compactly supported cohomology. We prove that, as a vector space, this compactly supported cohomology can be expressed as a certain polynomial functor applied to the reduced cohomology of X, and we relate the coefficients of this polynomial functor to so-called bead representations introduced by Turchin--Willwacher. Moreover we perform partial computations of these coefficients, and these computations lead us to detect a large number of homology classes for the moduli space M2,n; these classes live in the virtual cohomological dimension as well as one degree below.

    Paper III studies cohomological properties of a certain category of polynomial outer functors, and more precisely the Ext-groups between the simple objects of this category. In this paper I prove vanishing results in a certain range, and also detect that certain terms do not vanish outside that range. This contrasts with results of Vespa about the whole category of (non-necessarily outer) polynomial functors.

    Paper IV, written jointly with Dan Petersen, studies the handlebody mapping class group. In this paper we give a novel geometric model for a classifying space for these groups, using hyperbolic geometry, and use this description to detect a vast number of classes in their homology. At the end of the paper we use the classifying space constructed to provide a map between two spectral sequences, one computing the compactly supported cohomology of the tropical moduli space Mg,ntrop and the other one computing the weight zero part of the compactly supported cohomology of Mg,n; we conjecture that this map provides an isomorphism between the two spectral sequences.

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  • Public defence: 2024-06-14 10:00 ALB auditorium 3, house 2, Albano, Stockholm
    Pinheiro Astone, Daniel Augusto
    Stockholm University, Faculty of Law, Department of Law.
    Living as a commodity: Law, exploitation and the trade on human lives2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This dissertation investigates the role of the law in affording the conditions of possibility for exploitation to install and reproduce itself in the context of contemporary capitalism. It engages with the dialectical incompossibility of some of the key normative assumptions embedded in the law and the economy vis-à-vis their phenomenological consequences. With support from Niklas Luhmann’s systems theory, the dissertation relies on two main examples – patents on essential medicines and labour exploitation – to examine the tension between expropriation and accumulation. It advances the novel concept of “ablegality” as a register for the remainder that every phenomenological-hermeneutic operation will inevitably generate as the potentiality that accompanies all phenomenological reduction. The principal contribution made through this dissertation lies in articulating the role of the invisibilised side of legal operations as drivers for exploitation and, ultimately, for injustice to manifest legally.

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  • Public defence: 2024-06-14 13:00 hörsal 4, hus 2, Albano, Stockholm
    Wassénius, Emmy
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Royal Swedish Academy of Sciences, Sweden.
    Sustainability Risk: A social-ecological systems perspective2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Today’s world is characterised by new levels of complexity; however our societies remain deeply embedded in and dependent on a functioning biosphere. A biosphere that is increasingly being degraded by human activities. In this complex and intertwined world, acute shocks as well as chronic pressures of unsustainable activities have therefore become a prevalent feature. Together these shocks and chronic pressures create a complex risk landscape that we need to navigate with inter- and transdisciplinary solutions. However, the study of risk and the risk assessment tools in use, are siloed into scholarly disciplines and mismatched with the complexity at hand. In this thesis I tackle this mismatch, by using a social-ecological systems perspective and a variety of methodological approaches. Together the four papers of the thesis develop the interdisciplinary concept of sustainability risk and start to operationalise it through the application to national food systems and corporate sustainability risk assessment. Paper I introduces the concept of sustainability risk that I use and develop through-out the thesis. The paper also summarises some of the key definitions of risk within different disciplines and proposes five key dimensions that need to be adapted and developed in order for the existing risk assessment methods to fully capture risks in a complex world. Papers II-IV all represent applications of the concept of sustainability risk to different contexts. Paper II addresses national food supply risks and highlights how diverse risks to national self-sufficiency can come from low self-sufficiency (resulting in risk from trade disruptions) and low production diversity (resulting in risk from production shocks). Paper III addresses the data limitations we encounter when attempting to assess corporate sustainability risk and aims to overcome some of these limitations by developing fifteen novel reporting variables. These variables also contribute to the ongoing efforts to standardise corporate sustainability reporting. Paper IV builds on Paper III and develops an initial framework for assessing the risks to long-term natural resource production emanating from the impacts of corporate activities, thus broadening the conceptualisation of what risk is and how we assess it in the corporate sphere. 

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  • Public defence: 2024-06-14 13:00 online via Zoom, Stockholm
    Saadattalab, Vahid
    Stockholm University, Faculty of Science, Department of Materials and Environmental Chemistry (MMK).
    From blue hydrochars to activated carbons: Hydrothermal carbonization, chemical activation and gas adsorption2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Hydrothermal carbonization (HTC) of carbohydrates and biomass is a straightforward method for preparing hydrochars at low temperatures of 180-250 °C. Hydrochars are more carbonized than their precursors. Increasing the carbonization degree of hydrochars at hydrothermal temperatures is a scientific quest that is addressed in this thesis. Hydrochars are known to have a spherical or irregular morphology. Here we address thin film hydrochars for the first time.  Hydrochars themselves are carbon precursors for preparing activated carbons. Activated carbons are porous materials that can be used for gas adsorption applications. In this thesis, enhanced adsorption of VOCs at low pressures is addressed by using iron phosphate impregnated activated carbons. Finaly, any chemical process or product including those in this thesis such as HTC, activation, hydrochar and activated carbons may contribute to the issue of environmental degradation positively or negatively. Such environmental impacts are addressed by life cycle assessment of processes of HTC and activation and their related products in the last paper of this thesis. Briefly mentioned, in my first study (Paper I), I focused on the HTC of glucose in the presence of iron (II) sulfate. By changing the concentration of iron (II) sulfate, with a catalytic amount, blue hydrochars were formed at the bottom of the autoclave. The blueness was related to thin film interference. The thin film hydrochars were more carbonized than spherical hydrochars and the yield of HTC has increased in the presence of iron (II) sulfate. The second study (Paper II) is focused on the activation of hydrochars with H3PO4 and H3PO4+FeCl3. We showed that ultramicroporosity and impregnated iron phosphate species enhance the adsorption of VOCs at low pressure. The ACs were impregnated with Fe (PO3)2 and it was shown that Fe (PO3)2 acts as an activation agent which opens up for future studies. In the third study (Paper III), H3PO4-activated carbons were prepared and modified with FeS and FeSe and it was shown that the ACs were also impregnated with Fe2P, in the case of AC-FeS/Fe2P. FeSe and FeS were not detected by XRD. Only large crystals of Fe2P were detected in the sample AC-FeS/Fe2P. In the last study (Paper IV), prickly pear seed biomass from the agro sector in Tunisia was hydrothermally carbonized. The hydrochars were then activated into ACs by CO2 activation. The life cycle assessment of the HTC and activation process was investigated.  

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  • Public defence: 2024-06-14 13:00 Hörsal 9, hus D, Stockholm
    Elmerot, Irene
    Stockholm University, Faculty of Humanities, Department of Slavic and Baltic Studies, Finnish, Dutch, and German.
    Decoding Discourse: A corpus linguistic study of evaluative adjectives and group nouns in Czech print news media (1989–2018)2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This compilation thesis takes a top-down perspective on the representation of different groups of people in Czech news press over three decades. The starting point is that human equality is a global prerequisite for a democratic world, according to the United Nations Sustainable Development Goals. The research questions for the thesis concern how positively or negatively different groups of people are represented, and how often the different groups appear compared to each other. The thesis contributes results based on a language other than English, which represents a valuable contribution to the field.

    Theoretically, focus is on the premise that language is a tool for gaining and maintaining power, and a way of expressing power relations (Reisigl & Wodak 2016; Fairclough 2015). An important theoretical focus is the phenomenon of linguistic othering (Fidler 2016), which here means letting a group of people stand out from a certain news description by emphasising some of their characteristics. They then form what is also called an outgroup, as opposed to the ingroup that the writer is assumed to be part of (van Dijk 1987). The findings of this thesis provide insights into how news media can influence our perceptions of, for example, different nationalities or professions, linked to their socio-economic status, and by extension how these perceptions can influence our attitudes and behaviours towards these groups.

    Methodologically, the thesis uses corpus-based discourse analysis. Empirically, the research is based on the Czech National Corpus (www.korpus.cz). From this corpus, 32 million observations are extracted of when positive and negative adjectives, classified according to a subjectivity lexicon, appear in the news press together with nouns for different kinds of groups of people, such as gendered words like “woman” or “man”, occupations like “maid” or “miner” and nationalities like “Somali” or “Dane”. When adjectives are closer to nouns, or even next to them, they are given more weight than when they are more distant (Cvrček 2014). With such large amounts of data, a top-down or bird’s eye view is the most reasonable, but some detailed analyses are also included.

    Study I focuses on the representation of nationalities and countries, classified by the World Bank into groups according to their gross national income, and their co-occurrence with the positive and negative adjectives. Results: the nationalities in the different income groups are represented in a descending order; the higher the national income, the more positive the representation. Furthermore, discourses related to the so-called war on terror, as well as the security of different nations, emerge as a result of the analysis.

    Study II focuses on two groups, a focus group of Arabs and Muslims and a reference group of the other nationalities and countries. The focus group is a very heterogeneous group of people and countries that is often portrayed in the context of conflict (Baker et al., 2013, pp. 2 and 32). Results: Arabs and Muslims are consistently represented as an out-group, which over time affects how the people who read these news media view them.

    Study III contains two sub-studies, based on an intersectional analysis of modern Czech news reporting; in one sub-study the analysis focuses on professional roles, and in the other on different nouns for women and men. Results: Those with lower socio-economic status and fewer supervisory roles in their work are less likely to appear in news coverage, but when they do appear, it is not always with more negative representations. Regarding gender, men are more often portrayed than women, and women are more often represented by evaluative adjectives than men. In addition, women’s positive representations are based to a greater extent on their appearance and feelings, while men’s representations are based on their importance and competence.

    Overall, the results confirm quantitatively, with an empirical material covering almost the entire print news reporting in the Czech Republic since democratisation, that hypotheses that have been theoretically proposed, as well as confirmed, for other countries, turn out to be true for Czech news reporting. There are systematic differences in the way that some groups of people are significantly more often represented in the media than others, and that some groups are systematically represented more favourably than others. It also shows that these imbalances are clearly linked to factors such as nationality, occupation and gender.

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    Decoding Discourse: A corpus linguistic study of evaluative adjectives and group nouns in Czech print news media (1989–2018)
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  • Public defence: 2024-06-14 13:00 FD5, floor 5, AlbaNova, Stockholm
    Georgiev, Ivelin
    Stockholm University, Faculty of Science, Department of Astronomy.
    Studies of the intergalactic medium during the Epoch of Reionization: Understanding observational probes with simulations2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The first billion years of the Universe is a unique era, marked by the formation of the first stars, galaxies, and accreting black holes, which release ionising radiation into the intergalactic medium (IGM). As a result, these luminous sources initiate a period during which the cold and dense IGM, primarily consisting of neutral hydrogen (HI), is heated and ionised. We refer to this era as the Epoch of Reionization (EoR). The EoR is a global phase transition that is not trivial to observe or model computationally. It is a multi-scale event that evolves with time and depends on the nature of the astrophysical processes that govern the formation of stars and galaxies, as well as the fundamental cosmology that defines the properties of the large-scale IGM. While various measurements of cosmic reionization exist, presently they are too few to constrain the entirety of the process. However, observations from the James Webb Space Telescope and the Square Kilometre Array (SKA), among others, will provide new insight into the process. Particularly, the SKA will observe the power spectrum (PS) of the 21 cm signal from the EoR, which originates from the hyperfine transition of neutral hydrogen atoms HI in the IGM that can emit 21 cm photons. 

    In Paper I, we investigate the evolution of the 21 cm PS across the EoR by perturbing the signal and studying its composing terms. We highlight the importance higher-order terms play in shaping the PS on large scales and quantify its evolution. Crucially, we find a characteristic length scale within the 21 cm PS, determined by the mean free path ionising photons travel in the IGM (MFP). Hence, the 21 cm PS has two regimes. We show that the large-scale signal is a biased version of the cosmological density field, and the small-scale PS is determined by the astrophysics of reionization. In Paper II, we use the decomposition of the 21 cm PS and relate it to the PS of the free electron density field. Thus, we analytically connect the 21 cm observable to a probe of the free electron density field. Such a probe is the patchy kinetic Sunyaev-Zel'dovich effect (pkSZ), observed as a foreground to the primary cosmic microwave background temperature anisotropies on small scales. The pkSZ is an integrated probe sensitive to the duration of the EoR and the characteristic size of ionised bubbles. We construct a forecast study of both probes. We show that inferences from 21 cm PS from the SKA can be verified when combined with the pkSZ observation, as each data set is influenced by different systematics. In Paper III, we focus on the modelling of the MFP within large-scale simulations, focusing on the end of reionization (EndEoR). The MFP of ionising photons is inferred from quasar data and depends on several factors. In the post-EoR era, it depends on the distribution and evolution of Lyman Limit systems (LLS), small-scale absorbers that are typically not resolved in large-scale simulations. We investigate the assumptions needed to accurately model the LLS in simulations, and we study their impact on the observables at the EndEoR. We find that LLS modelling has a profound impact on the duration of the final stages of the EoR, the shape of the 21 cm PS as well as other observables of the ionised IGM inferred from quasar spectra, such as the Ultraviolet Background of ionising photons, the effective optical depth of Lyman alpha photons, and the MFP of ionising photons.

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    Studies of the intergalactic medium during the Epoch of Reionization: Understanding observational probes with simulations
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