Eternally accelerating spacelike braneworld cosmologies

TL;DR

This paper constructs models of eternally inflating spacelike branes in string and M-theory, showing how specific form fields induce exponential expansion while extra dimensions remain static or vary.

Contribution

It introduces a new class of eternally inflating spacelike brane models with explicit conditions for static or dynamic extra dimensions based on form fields.

Findings

Certain brane configurations lead to exponential expansion with static extra dimensions.

The size of perpendicular hyperbolic space remains constant in specific models.

Extra space varies in size in other configurations.

Abstract

We construct an eternally inflating spacelike brane world model. If the space dimension of the brane is three (SM2) or six (SM5) for M theory or four (SD3) for superstring theory, a time-dependent $n$-form field would supply a constant energy density and cause exponentially expansion of the spacelike brane. In these cases, the hyperbolic space perpendicular to the brane would not vary in size. In the other cases, however, the extra space would vary in size.