Higher-loop string cosmology with moduli and antisymmetric tensor field

Abstract

The classical evolution of a homogeneous cosmological model is investigated within the framework of low-energy effective string gravity with higher-genus corrections. Various conformal frames are considered. For the general case of correction functions in the Lagrangian we derive the cosmological solutions with arbitrary curvature and dilaton, modulus and Kalb-Ramond fields. These solutions are given in closed form in terms of integrations depending on dilaton coupling functions and generalize previously known tree-level solutions. The features of the solutions are discussed.