Spectrum from an Initially Anisotropic Universe

Abstract

We revisit the issue on signatures of pre-inflationary background anisotropy by considering the quantization of a massless and minimally coupled scalar field in an axially symmetric Kasner background, mimicking cosmological perturbations. We show that the power spectrum of the scalar field fluctuation has a negligible difference from that in the standard inflation in the non-planar directions, but it has a sharp peak around the symmetry plane. This note is based on our recent paper (Kim and Minamitsuji, JCAP 1103:038, 2011). © Springer-Verlag Berlin Heidelberg 2014.