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Primordial anisotropies from cosmic strings during inflation

Published version
Peer-reviewed

Type

Article

Change log

Authors

Sadr, AV 
Firouzjahi, H 

Abstract

In this work we study the imprints of a primordial cosmic string on inflationary power spectrum. Cosmic string induces two distinct contributions on curvature perturbations power spectrum. The first type of correction respects the translation invariance while violating isotropy. This generates quadrupolar statistical anisotropy in CMB maps which is constrained by the Planck data. The second contribution breaks both homogeneity and isotropy, generating a dipolar power asymmetry in variance of temperature fluctuations with its amplitude falling on small scales. We show that the strongest constraint on the tension of string is obtained from the quadrupolar anisotropy and argue that the mass scale of underlying theory responsible for the formation of string can not be much higher than the GUT scale. The predictions of string for the diagonal and off-diagonal components of CMB angular power spectrum are presented.

Description

Keywords

astro-ph.CO, astro-ph.CO, gr-qc, hep-th

Journal Title

Physical Review D

Conference Name

Journal ISSN

2470-0010
2470-0029

Volume Title

96

Publisher

American Physical Society (APS)

Rights

Publisher's own licence