The Shape of Gravity in a Warped Deformed Conifold

TL;DR

This paper analyzes the spectrum of gravitational modes in a warped deformed conifold within superstring theory, revealing how KK modes and gravitons distribute and tunnel, with implications for reheating after brane inflation.

Contribution

It provides the first detailed KK spectrum and tunneling probabilities for gravitational modes in a warped deformed conifold, including resonance effects impacting cosmological reheating.

Findings

KK modes are peaked in the throat, gravitons are uniformly distributed

Tunneling probabilities can be resonantly enhanced between throats

KK mode probability in the bulk can match that of the graviton

Abstract

We study the spectrum of the gravitational modes in Minkowski spacetime due to a 6-dimensional warped deformed conifold, i.e., a warped throat, in superstring theory. After identifying the zero mode as the usual 4D graviton, we present the KK spectrum as well as other excitation modes. Gluing the throat to the bulk (a realistic scenario), we see that the graviton has a rather uniform probability distribution everywhere while a KK mode is peaked in the throat, as expected. Due to the suppressed measure of the throat in the wave function normalization, we find that a KK mode's probability in the bulk can be comparable to that of the graviton mode. We also present the tunneling probabilities of a KK mode from the inflationary throat to the bulk and to another throat. Due to resonance effect, the latter may not be suppressed as natively expected. Implication of this property to reheating after brane inflation is discussed.