Cosmological implications from O(D, D)

Double field theory (DFT) offers a manifest O(D, D) formulation for massless closed string field theory with both momentum and winding excitations. The gauge symmetry is defined by the generalized Lie derivative which is the extension of the Courant bracket. In this work, we solve and study the properties of FRW (Friedmann-Robertson-Walker) and doubled spherically symmetric metric of DFT. Double field theory (DFT) offers a manifest O(D,D) formulation for massless closed string field theory with both momentum and winding excitations. The gauge symmetry is defined by the generalized Lie derivative which is the extension of the Courant doubled spherically symmetric metric of DFT.