Leonardo Gualtieri

University of Rome La Sapienza

Oscillation and stability of black holes in dynamical Chern-Simons gravity

In Dynamical Chern-Simons modified gravity the gravitational field is coupled with a scalar field through a parity-violating Chern-Simons term. In this framework, we study oscillations and stability of spherically symmetric black holes in the case of vanishing scalar field in the background. We find unstable modes when the coupling parameter beta is smaller than about 10^-2 km^-2, a value much larger than the bound derived from astrphysical observations. Further preliminary results suggest that spherically symmetric black holes in DCS modified gravity are unstable, even for larger values of beta.