Perturbations and quasinormal modes of black holes in modified theories of gravity
PT-CERN Call 2021/2
Instituto Superior Técnico (Universidade de Lisboa)
CENTRA - Center for astrophysics and gravitation
This project is centered around properties of black holes with higher derivative corrections from string theory. We will perform a complete study of linear perturbations of astrophysically relevant black holes in such higher curvature theories of gravity. We will also consider applications to the dual conformal field theories, through the AdS/CFT correspondence. First, we address asymptotically flat spherically symmetric black hole solutions in d dimensions with leading string-theoretical corrections. Here, we compute the different kinds of gravitational perturbations, study their stability and obtain the corresponding spectra of quasinormal modes in different limits. Moreover, we compute the greybody factors of these black holes. Then, we build new analytical rotating black hole solutions with leading string-theoretical higher order corrections in d=5 dimensions. For these solutions in d=4 and 5 we also study their gravitational perturbations, stability and obtain the corresponding spectra of quasinormal modes, greybody factors and shadows. We also perform these perturbative calculations for asymptotically AdS black holes with higher derivatives in d dimensions. In particular, for d=4 Einsteinian cubic gravity we will translate the output of the gravitational perturbation analysis to three dimensional CFTs to which the theory is dual to, through the AdS/CFT correspondence. We then study the phase structure of these CFTs.