Speaker: Rodrigo Fontana (Universidade Federal da Fronteira do Sul - UFFS Chapecó)
Title: Quasinormal modes of black holes: field propagation and stability.
Abstract: The propagation of probe fields around black hole geometries is an interesting tool for the investigation of two important aspects: the quasinormal mode spectrum and the stability of these geometries. In general, for simple enough metrics (e. g., spherically symmetric metrics), the field equations reduce to a wave-like equation with a specific potential. This turns the problem into a wave scattering problem with a potential barrier similar to that of a Schrödinger equation in quantum mechanics. With proper boundary conditions the spectrum is that of damped waves characterized by quasinormal modes. These quasinormal modes represent the characteristic response of black holes to linear perturbations and also give information about the stability of the geometry. In this talk. in the context of the Horndeski theory. I will present examples of quasinormal modes of black hole geometries in which a non-minimally coupled scalar field acts. Destabilization of these geometries will also be discussed. In addition, by using the same tools of field propagation, I will present results related to the violation of strong cosmic censorship in electric charged geometries.
This Seminar is joint with CAMGSD, and will be held at 14:00 - 15:00 in the DF meeting room on Level 2.