Can induced gravity isotropize Bianchi I, V, or IX Universes?

TL;DR

This paper investigates whether Bianchi I, V, and IX cosmological models in Induced Gravity can evolve into isotropic FRW universes, highlighting the role of the coupling parameter and potential in driving inflation and symmetry breaking.

Contribution

It extends analytical results from Brans-Dicke theory to Induced Gravity, showing how the coupling parameter influences isotropization and inflation in anisotropic cosmologies.

Findings

Isotropization depends on the value of mma.

Small mma allows for inflationary solutions.

Bianchi V model exhibits inflation and symmetry breaking leading to FRW evolution.

Abstract

We analyze if Bianchi I, V, and IX models in the Induced Gravity (IG) theory can evolve to a Friedmann--Roberson--Walker (FRW) expansion due to the non--minimal coupling of gravity and the scalar field. The analytical results that we found for the Brans-Dicke (BD) theory are now applied to the IG theory which has $\omega \ll 1$ ($\omega$ being the square ratio of the Higgs to Planck mass) in a cosmological era in which the IG--potential is not significant. We find that the isotropization mechanism crucially depends on the value of $\omega$. Its smallness also permits inflationary solutions. For the Bianch V model inflation due to the Higgs potential takes place afterwads, and subsequently the spontaneous symmetry breaking (SSB) ends with an effective FRW evolution. The ordinary tests of successful cosmology are well satisfied.