Scalar waves from a star orbiting a BTZ black hole

Abstract

In this paper we compute the decay rates of massless scalar waves excited by a star circularly orbiting around the non-extremal (general) and extremal BTZ black holes. These decay rates are compared with the corresponding quantities computed in the corresponding dual conformal field theories respectively. We find that matches are achieved in both cases.

In v2, 17 pages, title changed (contents not changed), discussion of the isometry group of the near-horizon-extremal BTZ geometry and its effects on the solutions is added, references added. V3, minor corrections, several more references added