Investigating brane resolution with perturbative dynamics

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. (author)