Infrared Hierarchy, Thermal Brane Inflation and Superstrings as Superheavy Dark Matter

TL;DR

This paper explores how thermal effects in brane-world scenarios can induce a brief inflationary period, leading to superstrings that could serve as superheavy dark matter.

Contribution

It introduces a novel mechanism where thermal stabilization of branes causes inflation and produces superstrings as dark matter candidates.

Findings

Thermal effects can temporarily stabilize branes, inducing inflation.

Superstrings stretched between separated branes can account for superheavy dark matter.

The model predicts a specific density of superstrings consistent with dark matter observations.

Abstract

In theories with TeV scale quantum gravity the standard model particles live on a brane propagating in large extra dimensions. Branes may be stabilized at large (sub-millimeter) distances from each other, either due to weak Van der Waals type interactions, or due to an infrared analog of Witten's inverse hierarchy scenario. In particular, this infrared stabilization may be responsible for a large size of extra dimensions. In either case, thermal effects can drive a brief period of the late inflation necessary to avoid the problems with high reheating temperature and the stable unwanted relics. The main reason is that the branes which repel each other at zero temperature can be temporarily glued together by thermal effects. It is crucial that the temperature needed to stabilize branes on top of each other can be much smaller than the potential energy of the bound-state, which drives inflation. After 10-15 $e$-foldings bound-states cool below the critical temperature and decay ending inflation. The parallel brane worlds get separated at this stage and superstrings (of a sub-millimeter size) get stretched between them. These strings can have the right density in order to serve as a superheavy dark matter.