Authors: João G Rosa
Publish Date: 2013/02/04
Volume: 2013, Issue: 2, Pages: 14-
Abstract
We study the formation of superradiant bound states for massive scalar fields in fivedimensional rotating black string geometries with a nonvanishing KaluzaKlein momentum along the compact direction Even though all KaluzaKlein modes may form bound states in this geometry in realistic extradimensional models and astrophysical black holes only the zeromode is sufficiently light for superradiant instabilities to develop provided the field has a small but nonvanishing mass as for example for axionlike particles We use analytical and numerical methods to show that although the KaluzaKlein momentum decreases the upper bound on the field mass for an instability to develop it may enhance its maximum growth rate by more than 50 thus boosting the black hole bomb mechanism We discuss the possible observational consequences of this result and its potential as an astrophysical probe of nontrivial extradimensional compactifications
Keywords: