NBIA Gravity Seminar: Marc Casals

Speaker: Marc Casals

Title: Black hole spectroscopy: stability, censorship and Love


The investigation of how black holes react to field perturbations helps us understand better these enigmatic objects in the Universe. The decomposition into frequency modes of the field perturbations of black holes, analogously to atomic spectroscopy, is particularly useful. In this talk, we will present three different results obtained from such spectroscopy studies of rotating (Kerr) black holes. The first result is on the linear stability properties of Kerr, including a horizon instability in the maximally-rotating limit. The second result is evidence for the violation of Penrose’s strong cosmic censorship hypothesis for charged Kerr black holes in a Universe with a positive cosmological constant (de Sitter), thus indicating a possible breakdown of the predictability of Einstein’s equations inside these black holes. Time allowing, we will also present a last result on the deformability of Kerr black holes under an external static gravitational field, as measured by the so-called Love numbers.