Aspectos modernos em buracos negros

Abstract

In this thesis, we study the process of scattering massless scalar waves due to different black hole scenarios, such as the effects of noncommutative via Lorentzian smeared mass distribution, the implementation of quantum corrections in the Schwarzschild metric using the generalized uncertainty principle (GUP), and self-dual black hole. We use different methods to investigate the scattering process at the low and high frequencies limit, mainly the partial wave method, and numerical analysis to verify the results. We determined the phase shift analytically at the low energy limit and saw that the absorption cross section and the differential scattering cross section are modified by the corrections in each scenario. In all scenarios we find that the absorption is not zero as the mass parameter goes to zero. We complement it with the study of quasinormal modes using two different methods: The first is the Wentzel-Kramers-Brillouin (WKB) approximation with corrections up to the sixth order implemented by Konoplya and the second is the numerical analysis introduced by Leaver. We noticed that both the noncommutativity and the corrections introduced with the GUP modify the behavior of quasinormal frequencies. Furthermore, we investigated the black hole shadow radius in these two scenarios and verified the relationship with the quasinormal modes in the eikonal regime.