Quantum tunneling and the cosmic censorhip conjecture

Author(s)

Maurício Richartz

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Física Gleb Wataghin
• Defense date: 2011-03-31

Examining board members

Alberto Vazquez Saa; Patricio Anibal Letelier Sotomayor; Carlos Ourivio Escobar; Gilberto Medeiros Kremer; Vicente Pleitez

• Advisor: Amir Ordacgi Caldeira; Alberto Vazquez Saa

Abstract

The Cosmic Censorship Conjecture, proposed by Roger Penrose in 1969, asserts that singularities arising from the gravitational collapse of a body are always encompassed by the event horizon of a black hole. The main purpose of this work is to investigate quantum tunneling processes whose objetive is to violate this conjecture. Using the Newman-Penrose formalism, scalar, neutrino, electromagnetic and gravitational perturbations in both Kerr and Reissner-Nordstrom metrics are analysed. Wave scattering processes in these metrics are studied and transmission and reflection coecients for incident waves are calculated in the limit of small energies. From these results, gedanken experiments with the purpose of destroying the event horizon of a black hole and exposing its inner singularity to an external observer are proposed and analysed. Superradiance, phenomenum in which incident waves are amplified when reflected by a scattering potential, manifests itself in these thought experiments and, therefore, is also treated in detail in this work. Finally, some experiments with the purpose of detecting Hawking radiation and superradiance in analogue models of gravity are analysed. In particular, an experiment proposed by me, in collaboration with Silke Weinfurtner, whose aim is to investigate the possibility of superradiance detection in laboratory, is discussed (AU)