Double Field Theory Inspired Cosmology

TL;DR

This paper explores cosmological solutions within double field theory, demonstrating a smooth transition from early anisotropic to later isotropic phases, and highlighting the theory's advantages over standard string cosmology in modeling universe evolution.

Contribution

It introduces a novel approach to cosmological solutions in double field theory, unifying pre- and post-big bang phases and naturally incorporating extra dimensions.

Findings

Smooth transition from anisotropic to isotropic universe

Automatic inflation and decelerated expansion phases

More consistent solutions than standard string cosmology

Abstract

Double field theory proposes a generalized spacetime action possessing manifest T-duality on the level of component fields. We calculate the cosmological solutions of double field theory with vanishing Kalb-Ramond field. It turns out that double field theory provides a more consistent way to construct cosmological solutions than the standard string cosmology. We construct solutions for vanishing and non-vanishing symmetry preserving dilaton potentials. The solutions assemble the pre- and post-big bang evolutions in one single line element. This novel feature provides a natural way for the theory to contain extra dimensions. Our results show a smooth evolution from an anisotropic early stage to an isotropic phase without any special initial conditions in contrast to previous models. In addition, we demonstrate that the contraction of the dual space automatically leads to both an inflation phase and a decelerated expansion of the ordinary space during different evolution stages.