Supersymmetric Godel Universes in String Theory

TL;DR

This paper explores supersymmetric Godel Universe solutions in string and M-theory, discovering new backgrounds with high supersymmetry, analyzing dualities, and computing spectra of strings and D-branes in these geometries.

Contribution

It introduces several new supersymmetric Godel Universes, including one in M-theory with 18 supersymmetries, and demonstrates how dualities relate these backgrounds to pp-waves.

Findings

Discovered Godel Universes with up to 20 supersymmetries.

Showed T-duality and S-duality generate supersymmetric Godel Universes from pp-waves.

Computed string spectra and D-brane configurations on Godel Universes.

Abstract

Supersymmetric backgrounds in string and M-theory of the Godel Universe type are studied. We find several new Godel Universes that preserve up to 20 supersymmetries. In particular, we obtain an interesting Godel Universe in M-theory with 18 supersymmetries which does not seem to be dual to a pp-wave. We show that not only T-duality but also the type-IIA/M-theory S-duality can give supersymmetric Godel Universes from pp-waves. We find solutions that can interpolate between Godel Universes and pp-waves. We also compute the string spectrum on two type IIA Godel Universes. Furthermore, we obtain the spectrum of D-branes on a Godel Universe and find the supergravity solution for a D4-brane on a Godel Universe.