Double field theory inspired cosmology

Abstract

Double field theory proposes a generalized spacetime actionpossessing manifest T-duality on the level of component fields. Wecalculate the cosmological solutions of double field theory withvanishing Kalb-Ramond field. It turns out that double field theoryprovides a more consistent way to construct cosmological solutionsthan the standard string cosmology. We construct solutions for vanishing and non-vanishing symmetry preserving dilaton potentials. The solutions assemblethe pre- and post-big bang evolutions in one single line element.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.