Change search
ReferencesLink to record
Permanent link

Direct link
Cosmological viability of massive gravity with generalized matter coupling
Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
Show others and affiliations
2015 (English)In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, no 4, 027Article in journal (Refereed) Published
Abstract [en]

There is a no-go theorem forbidding flat and closed FLRW solutions in massive gravity on a flat reference metric, while open solutions are unstable. Recently it was shown that this no-go theorem can be overcome if at least some matter couples to a hybrid metric composed of both the dynamical and the fixed reference metric. We show that this is not compatible with the standard description of cosmological sources in terms of effective perfect fluids, and the predictions of the theory become sensitive either to the detailed field-theoretical modelling of the matter content or to the presence of additional dark degrees of freedom. This is a serious practical complication. Furthermore, we demonstrate that viable cosmological background evolution with a perfect fluid appears to require the presence of fields with highly contrived properties. This could be improved if the equivalence principle is broken by coupling only some of the fields to the composite metric, but viable self-accelerating solutions due only to the massive graviton are difficult to obtain. These problems can be avoided by giving the reference metric dynamics.

Place, publisher, year, edition, pages
2015. no 4, 027
Keyword [en]
modified gravity, dark energy theory
National Category
Astronomy, Astrophysics and Cosmology
URN: urn:nbn:se:su:diva-112950DOI: 10.1088/1475-7516/2015/04/027ISI: 000355742500028OAI: diva2:782015
Available from: 2015-01-19 Created: 2015-01-19 Last updated: 2015-07-21Bibliographically approved
In thesis
1. Cosmic tests of massive gravity
Open this publication in new window or tab >>Cosmic tests of massive gravity
2015 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Massive gravity is an extension of general relativity where the graviton, which mediates gravitational interactions, has a non-vanishing mass. The first steps towards formulating a theory of massive gravity were made by Fierz and Pauli in 1939, but it took another 70 years until a consistent theory of massive gravity was written down. This thesis investigates the phenomenological implications of this theory, when applied to cosmology. In particular, we look at cosmic expansion histories, structure formation, integrated Sachs-Wolfe effect and weak lensing, and put constraints on the allowed parameter range of the theory. This is done by using data from supernovae, the cosmic microwave background, baryonic acoustic oscillations, galaxy and quasar maps and galactic lensing.

The theory is shown to yield both cosmic expansion histories, galactic lensing and an integrated Sachs-Wolfe effect consistent with observations. For the structure formation, however, we show that for certain parameters of the theory there exists a tension between consistency relations for the background and stability properties of the perturbations. We also show that a background expansion equivalent to that of general relativity does not necessarily mean that the perturbations have to evolve in the same way.

Place, publisher, year, edition, pages
Stockholm: Department of Physics, Stockholm University, 2015. 104 p.
Modified gravity, massive gravity, cosmology, dark energy, dark matter
National Category
Astronomy, Astrophysics and Cosmology
Research subject
urn:nbn:se:su:diva-113076 (URN)978-91-7649-049-5 (ISBN)
Public defence
2015-02-20, sal FD5, AlbaNova Universitetscentrum, Roslagstullsbacken 21, Stockholm, 13:00 (English)

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 5: Manuscript. Paper 6: Manuscript.

Available from: 2015-01-29 Created: 2015-01-22 Last updated: 2015-08-24Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Enander, JonasMörtsell, Edvard
By organisation
The Oskar Klein Centre for Cosmo Particle Physics (OKC)
In the same journal
Journal of Cosmology and Astroparticle Physics
Astronomy, Astrophysics and Cosmology

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 73 hits
ReferencesLink to record
Permanent link

Direct link