Thesis

Collapse or collide: improved analysis of black hole formation mechanisms

• Call:

  PT-CERN Call 2022/1

• Academic Year:

  2022

• Domain:

  Astroparticle Physics

• Supervisor:

  Jorge Rocha

• Co-Supervisor:

  David Hilditch

• Institution:

  Instituto Superior Técnico (Universidade de Lisboa)

• Host Institution:

  CENTRA - Center for astrophysics and gravitation

• Abstract:

  For several decades black holes have played a central role in theoretical physics, and the last few years revealed they are more than constructs of human imagination: we can actually observe them. In the context of general relativity (GR), we have a very good understanding of how black holes are formed under gravitational collapse. Furthermore, there are some indications about how black holes can result from high energy collisions. However, all (semi-)analytic studies of black hole formation processes are overly simplistic in the sense that they adopt, at best, perfect fluids to describe the matter involved. Additionally, this knowledge is mostly based on the assumption that gravity is describer exactly by GR, even at scales where we would naturally expect quantum gravity to take over. This project proposes to further develop the studies of gravitational collapse and shock wave collisions. Relativistic elastic bodies will be considered in gravitational collapse and the impact of the matter’s elasticity in critical collapse and high energy collisions will be assessed. In addition, we will also consider the effect of higher curvature corrections to GR on processes that yield measurable signatures of gravity. Such modifications to gravity are expected to leave imprints on critical collapse, since this subject deals with the formation of black holes at arbitrarily small scales. Gravitational collapse in the near critical regime is particularly relevant to understand the distribution of primordial black holes and to investigate the production of very massive hypothetical particles as products of Hawking radiation. The specific behavior of collapse and compact object formation is particularly relevant to understand the evolution of the universe and and the nature of dark matter. Thus, while the research program aims to improve our present knowledge concerning black hole formation, it has also important implications for beyond-standard model physics and cosmology.