New non-perturbative de Sitter vacua in α′-complete cosmology

The alpha ' -complete cosmology developed by Hohm and Zwiebach classifies the O(d, d; ) invariant theories involving metric, b-field and dilaton that only depend on time, to all orders in alpha '. Some of these theories feature non-perturbative isotropic de Sitter vacua in the string frame, generated by the infinite number of higher-derivatives of O(d, d; ) multiplets. Extending the isotropic ansatz, we construct stable and unstable non-perturbative de Sitter solutions in the string and Einstein frames. The generalized equations of motion admit new solutions, including anisotropic d + 1-dimensional metrics and non-vanishing b-field. In particular, we find dS(n+1)x Td-n geometries with constant dilaton, and also metrics with bounded scale factors in the spatial dimensions with non-trivial b-field. We discuss the stability and non-perturbative character of the solutions, as well as possible applications.