Large scale anisotropy due to pre-inflationary phase of cosmic evolution

TL;DR

This paper explores how anisotropic conditions in the early universe's pre-inflationary phase could influence current cosmological observations, potentially explaining large-scale anisotropies like CMB alignments.

Contribution

It introduces a model linking early anisotropic phases to observable large-scale anisotropies in the CMB, offering explanations for phenomena such as quadrupole-octopole alignment.

Findings

Large scale anisotropic modes can influence CMB signals.

Pre-inflationary anisotropy may explain CMB quadrupole-octopole alignment.

Framework potentially accounts for observed dipole modulation in CMB.

Abstract

We show that perturbations generated during the anisotropic pre-inflationary stage of cosmic evolution may affect cosmological observations today for a certain range of parameters. Due to the anisotropic nature of the universe during such early times, it might explain some of the observed signals of large scale anisotropy. In particular we argue that the alignment of CMB quadrupole and octopole may be explained by the Sachs-Wolfe effect due to the large scale anisotropic modes from very early times of cosmological evolution. We also comment on how the observed dipole modulation of CMB power may be explained within this framework.