Scale-factor duality in string Bianchi cosmologies

TL;DR

This paper explores how scale factor duality transformations in string theory can be applied to anisotropic Bianchi cosmological models, revealing dual solutions and symmetry properties for most Bianchi types.

Contribution

It extends the application of scale factor duality to all Bianchi types except VIII and IX, providing explicit dual solutions and analyzing symmetry loss in the scalar field.

Findings

Dual models constructed for all Bianchi types except VIII and IX.

Explicit forms of dual solutions derived from original models.

Loss of initial homogeneity symmetry in dual Bianchi class B models.

Abstract

We apply the scale factor duality transformations introduced in the context of the effective string theory to the anisotropic Bianchi-type models. We find dual models for all the Bianchi-types [except for types $VIII$ and $IX$] and construct for each of them its explicit form starting from the exact original solution of the field equations. It is emphasized that the dual Bianchi class $B$ models require the loss of the initial homogeneity symmetry of the dilatonic scalar field.