Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Anisotropic non-gaussianity from rotational symmetry breaking excited initial states
Stockholm University, Nordic Institute for Theoretical Physics (Nordita).
Number of Authors: 3
2016 (English)In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 12, 002Article in journal (Refereed) Published
Abstract [en]

If the initial quantum state of the primordial perturbations broke rotational invariance, that would be seen as a statistical anisotropy in the angular correlations of the cosmic microwave background radiation (CMBR) temperature fluctuations. This can be described by a general parameterisation of the initial conditions that takes into account the possible direction-dependence of both the amplitude and the phase of particle creation during inflation. The leading effect in the CMBR two-point function is typically a quadrupole modulation, whose coefficient is analytically constrained here to be vertical bar B vertical bar less than or similar to 0.06. The CMBR three-point function then acquires enhanced non-gaussianity, especially for the local con figurations. In the large occupation number limit, a distinctive prediction is a modulation of the non-gaussianity around a mean value depending on the angle that short and long wavelength modes make with the preferred direction. The maximal variations with respect to the mean value occur for the con figurations which are coplanar with the preferred direction and the amplitude of the non-gaussianity increases (decreases) for the short wavelength modes aligned with (perpendicular to) the preferred direction. For a high scale model of inflation with maximally pumped up isotropic occupation and epsilon similar or equal to 0. 01 the difference between these two configurations is about 0. 27, which could be detectable in the future. For purely anisotropic particle creation, the non-Gaussianity can be larger and its anisotropic feature very sharp. The non-gaussianity can then reach f(NL)similar to 30 in the preferred direction while disappearing from the correlations in the orthogonal plane.

Place, publisher, year, edition, pages
2016. no 12, 002
Keyword [en]
CMBR theory, cosmological perturbation theory, inflation, non-gaussianity
National Category
Physical Sciences
Identifiers
URN: urn:nbn:se:su:diva-142418DOI: 10.1088/1475-7516/2016/12/002ISI: 000398395400044OAI: oai:DiVA.org:su-142418DiVA: diva2:1092623
Available from: 2017-05-03 Created: 2017-05-03 Last updated: 2017-05-03Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Koivisto, Tomi
By organisation
Nordic Institute for Theoretical Physics (Nordita)
In the same journal
Journal of Cosmology and Astroparticle Physics
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar

Altmetric score

Total: 11 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf