Accelerating Universes from Compactification on a Warped Conifold

Abstract

We find a cosmological solution corresponding to compactification of 10d supergravity on a warped conifold that easily circumvents `no-go' theorem given for a warped/flux compactification, providing new perspectives for the study of supergravity or superstring theory in cosmological backgrounds. With fixed volume moduli of the internal space, the model can explain a physical universe undergoing an accelerated expansion in the 4d Einstein frame, for a sufficiently long time. The solution found in the limit that the warp factor dependent on the radial coordinate $y$ is extremized (giving a constant warping) is smooth and it supports a flat four-dimensional Friedmann-Robertson-Walker cosmology undergoing a period of accelerated expansion with slowly rolling or stabilized volume moduli.