Godel Universes in String Theory

Abstract

We show that homogeneous Gödel spacetimes need not contain closed timelike curves in low-energy-effective string theories. We find exact solutions for the Gödel metric in string theory for the full $O(α^{\prime})$ action including both dilaton and axion fields. The results are valid for bosonic, heterotic and super-strings. To first order in the inverse string tension $α^{\prime}$, these solutions display a simple relation between the angular velocity of the Gödel universe, $Ω,$ and the inverse string tension of the form $α^{\prime}=1/Ω^2$ in the absence of the axion field. The generalization of this relationship is also found when the axion field is present.