Deformations of Cosmological Solutions of D=11 Supergravity

TL;DR

This paper explores deformations of D=11 supergravity cosmological solutions using U(1) isometries, generating new solutions with nonzero flux and discussing implications for accelerating cosmologies after compactification.

Contribution

It introduces a method to generate new supergravity solutions with flux from Einstein solutions, including multiple overlapping S-branes and cosmological models.

Findings

Generated new supergravity solutions with multiple S-branes.

Constructed solutions with non-zero 4-form flux.

Discussed potential for accelerating cosmologies after compactification.

Abstract

We study Lunin-Maldacena deformations of cosmological backgrounds of D=11 supergravity which gives an easy way to generate solutions with nonzero 4-form flux starting from solutions of pure Einstein equations which possess at least three U(1) isometries. We illustrate this on the vacuum S-brane solution from which the usual SM2-brane solution is obtained. Applying the method again, one either gets the recently found S-brane system where contribution of the Chern-Simons term to field equations is non-zero or the SM2-SM2(0) intersection, depending on which U(1) directions are used during the process. Repeated usage of the procedure gives rise to configurations with several overlapping S-branes some of which are new. We also employ this method to construct two more new solutions and make comments about accelerating cosmologies that follow from such deformed solutions after compactification to (1+3)-dimensions.