Warped Reheating in Brane-Antibrane Inflation

TL;DR

This paper investigates how reheating after brane-antibrane inflation in warped geometries can efficiently transfer energy to the Standard Model brane, even when separated by multiple throats, facilitating realistic multi-throat models.

Contribution

It demonstrates that under certain conditions, energy from brane annihilation can significantly reach the Standard Model brane despite geometric separation, aiding multi-throat model construction.

Findings

Energy transfer to the Standard Model brane can be substantial with moderate warping.

Exponential growth of Kaluza-Klein modes enhances energy deposition.

Multi-throat models can reconcile inflation scale with supersymmetry breaking.

Abstract

We examine how reheating occurs after brane-antibrane inflation in warped geometries, such as those which have recently been considered for Type IIB string vacua. We adopt the standard picture that the energy released by brane annihilation is dominantly dumped into massive bulk (closed-string) modes which eventually cascade down into massless particles, but argue that the this need not mean that the result is mostly gravitons with negligible visible radiation on the Standard Model brane. We show that if the inflationary throat is not too strongly warped, and if the string coupling is sufficiently weak, then a significant fraction of the energy density from annihilation will be deposited on the Standard Model brane, even if it is separated from the inflationary throat by being in some more deeply warped throat. This is due to the exponential growth of the massive Kaluza-Klein wave functions toward the infrared ends of the throats. We argue that the possibility of this process removes a conceptual obstacle to the construction of multi-throat models, wherein inflation occurs in a different throat than the one in which the Standard Model brane resides. Such multi-throat models are desirable because they can help to reconcile the scale of inflation with the supersymmetry breaking scale on the Standard Model brane, and because they can allow cosmic strings to be sufficiently long-lived to be observable during the present epoch.