Separable Brane Cosmologies in Heterotic M-Theory

TL;DR

This paper demonstrates how anisotropic and inhomogeneous four-dimensional string cosmologies can serve as seeds to generate curved three-brane solutions in five-dimensional heterotic M-theory, linking weak and strong coupling regimes.

Contribution

It introduces a method to derive five-dimensional brane cosmologies from four-dimensional string solutions, establishing a formal connection between weakly and strongly coupled regimes.

Findings

Derived curved three-brane solutions from four-dimensional seed cosmologies.

Analyzed asymptotic behavior of spatially homogeneous braneworlds.

Extended solutions to massive type IIA supergravity.

Abstract

It is shown that any anisotropic and inhomogeneous cosmological solution to the lowest-order, four-dimensional, dilaton-graviton string equations of motion may be employed as a seed to derive a curved, three-brane cosmological solution to five-dimensional heterotic M-theory compactified on a Calabi-Yau three-fold. This correspondence formally relates a weakly coupled string cosmology directly with a strongly coupled one. The asymptotic behaviour of a wide class of spatially homogeneous braneworlds is deduced. Similar solutions may be derived in toroidally compactified massive type IIA supergravity.