Brane cosmology in the Horava-Witten heterotic M-Theory on $S^{1}/Z_{2}$

TL;DR

This paper investigates the stability and mass of the radion field in Horava-Witten heterotic M-Theory on an orbifold, analyzing gravitational localization, KK spectrum, and cosmological implications.

Contribution

It provides a detailed analysis of radion stability, mass, and gravitational spectrum in the HW heterotic M-Theory framework, including cosmological equations.

Findings

Radion is stable with a mass around GeV.

Gravity is localized on the visible brane with a discrete KK spectrum.

Higher KK mode corrections to Newtonian potential are exponentially suppressed.

Abstract

We study the radion stability and radion mass in the framework of the Horava-Witten (HW) heterotic M-Theory on $S^{1}/Z_{2}$, and find that the radion is stable and its mass can be of the order of GeV. The gravity is localized on the visible brane, and the spectrum of the gravitational Kaluza-Klein (KK) modes is discrete and can have a mass gap of TeV. The corrections to the 4D Newtonian potential from the higher order gravitational KK modes are exponentially suppressed. Applying such a setup to cosmology, we find the generalized Friedmann-like equations on each of the two orbifold branes.