Investigating Brane Resolution With Perturbative Dynamics

TL;DR

This paper explores how perturbative field dynamics can distinguish between singular and non-singular geometries, providing exact absorption probabilities and quasinormal modes for scalars in heterotic 5-brane backgrounds.

Contribution

It offers the first exact calculation of scalar absorption probabilities and quasinormal modes in heterotic 5-brane geometries, linking these to geometric singularities.

Findings

Absorption probability vanishes below a threshold frequency in singular geometries.

Absorption probability vanishes for all frequencies in non-singular geometries.

Exact quasinormal modes are obtained for the background.

Abstract

We investigate the transition between singular and non-singular geometries from the vantage point of perturbative field dynamics. In particular, we obtain the closed-form absorption probability for minimally-coupled massless scalars propagating in the background of a heterotic 5-brane on a Taub-NUT instanton. This is an exact calculation for arbitrary incident frequencies. For the singular geometry, the absorption probability vanishes when the frequency is below a certain threshold, and for the non-singular case it vanishes for all frequencies. We discuss the connection between this phenomenon and the behavior of geodesics in this background. We also obtain exact quasinormal modes.