Spectrum of Perturbations in Anisotropic Inflationary Universe with Vector Hair - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




Spectrum of Perturbations in Anisotropic Inflationary Universe with Vector Hair - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We study both the background evolution and cosmological perturbations ofanisotropic inflationary models supported by coupled scalar and vector fields.The models we study preserve the U1 gauge symmetry associated with the vectorfield, and therefore do not possess instabilities associated with longitudinalmodes which instead plague some recently proposed models of vector inflationand curvaton. We first intoduce a model in which the background anisotropyslowly decreases during inflation; we then confirm the stability of thebackground solution by studying the quadratic action for all the perturbationsof the model. We then compute the spectrum of the $h {\times}$ gravitationalwave polarization. The spectrum we find breaks statistical isotropy at thelargest scales and reduces to the standard nearly scale invariant form at smallscales. We finally discuss the possible relevance of our results to the largescale CMB anomalies.



Author: Burak Himmetoglu

Source: https://arxiv.org/







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