Cosmological tensor perturbations in the Randall-Sundrum model: evolution in the near-brane limit

TL;DR

This paper investigates how tensor perturbations evolve in the Randall-Sundrum II cosmological model, focusing on the near-brane limit to understand potential observable signatures of massive excitations.

Contribution

It introduces a method to analyze tensor perturbations in the RSII model using the near-brane limit for separation of variables, revealing decay of massive modes outside the horizon.

Findings

Massive excitations decay outside the horizon.

The near-brane limit enables separation of the wave equation.

Potential for novel cosmological signatures from perturbation mixing.

Abstract

We discuss the evolution of cosmological tensor perturbations in the RSII model. In Gaussian normal coordinates the wave equation is non-separable, so we use the near-brane limit to perform the separation and study the evolution of perturbations. Massive excitations, which may also mix, decay outside the horizon which could lead to some novel cosmological signatures.