Eternally inflating cosmologies from intersecting spacelike branes

TL;DR

This paper explores intersecting spacelike brane cosmologies, demonstrating the possibility of eternal inflation and static or shrinking extra dimensions, constrained by supersymmetry algebra in a higher-dimensional framework.

Contribution

It introduces a novel approach to cosmology using intersecting spacelike branes with multiple timelike metrics, showing conditions for eternal inflation and geometric restrictions from supersymmetry.

Findings

Achieved models of eternally inflating Robertson-Walker spacetime with extra dimensions.

Found that some dimensions can be static or shrink in multibrane solutions.

Identified supersymmetry constraints on the geometry of extra space.

Abstract

Intersecting spacelike braneworld cosmologies are investigated. The time axis is set on the scale parameter of extra space, which may include more than one timelike metric. Obtained are eternally inflating (i.e. undergoing late-time inflation) Robertson-Walker spacetime and extra space with a constant scale factor. In the case of multibrane solutions, some dimensions are static or shrink. The fact that the largest supersymmetry algebra contains 32 supercharges in 4 dimensions imposes a restriction on the geometry of extra space.