## Double Field Theory Inspired Cosmology    [PDF]

Houwen Wu, Haitang Yang
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 find two sets of solutions in double field theory cosmology, respecting or violating the strong (weak) constraint. Both sets of solutions naturally contain the pre- and post-big bang evolutions in one single line element. This novel feature opens a window for possible resolution of the cosmic amnesia. We also demonstrate that the scale factor duality in the standard string cosmology is nothing but the T-duality in double field theory. The scale dual dilatons in the standard string cosmology is simply the usual diffeomorphic scalar dilaton $\phi$ and dual diffeomorphic scalar dilaton $\tilde\phi$ in double field theory. Furthermore, we identify the "shifted dilaton" in the standard string cosmology with the $O(D,D)$ scalar dilaton $d$ in double field theory.
View original: http://arxiv.org/abs/1307.0159