Inflating Intersecting Branes and Remarks on the Hierarchy Problem

TL;DR

This paper extends intersecting brane solutions in higher-dimensional spacetimes to dynamic, expanding universes, revealing limitations of the Randall-Sundrum mechanism in addressing the hierarchy problem due to bulk inflation effects.

Contribution

It generalizes static intersecting brane solutions to nonstatic, expanding cases and analyzes their implications for gravity and the hierarchy problem.

Findings

Newton's constant tends to zero on the TeV brane

Gravity strength remains constant on the Planck brane

Bulk inflation affects the hierarchy mechanism

Abstract

We generalize solutions of Einstein's equations for intersecting branes in higher dimensional spacetimes to the nonstatic case, modeling an expanding universe. The relation between the Hubble rate, the brane tensions, and the bulk cosmological constant is similar to the case of a single 3-brane in a 5-dimensional spacetime. However, because the bulk inflates as well as the branes, this class of solutions suffers from Newton's constant tending toward zero on the TeV brane, where the Randall-Sundrum mechanism should solve the weak scale hierarchy problem. The strength of gravity remains constant on the Planck brane, however.