Black hole entropy and critical phenomena
IDPASC Portugal - PHD Programme 2016
2016 / 2017
General Relativity | Astrophysics
José Sande Lemos
Instituto Superior Técnico
The first direct detection of black holes, through the very recent gravitational wave event GW150914, urges the understanding of all physical effects related to black holes. In this connection, one of the outstanding problems is the issue of the black hole entropy that appears naturally when thermodynamics of these systems are taken into acount. Two questions, namely, where and what are the statistical mechanics degrees of freedom that give rise to the black hole entropy, have not yet been answered. It is now known that gravitational collapse of matter can lead to the formation of naked singularities at the threshold of black hole formation. It is also known that this behavior at the transition from matter dispersion to black holes, is related to the critical phenomena that appears in statistical physics at any phase transition of matter. Thus, black hole formation and black hole entropy are inter related issues, also connected to the physics at the event horizon and in its interior. A way to link these aspects is to consider matter systems, either in quasistatic or dynamical collapse, and understand how both the entropy and the critical phenomena emerge in these situations. The main aim of this Ph.D. thesis is to study in detail the emergence of criticality and entropy in black hole theory. The results will be compared to other related approaches, such as the stringy fuzzball model and some manifestations of the AdS/CFT conjecture, and to the reported instability of AdS spacetime.