Thesis

Collapse or collide: improved analysis of black hole formation mechanisms

• Call:

  PT-CERN Call 2021/2

• Academic Year:

  2021

• 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, we have a very good understanding of how black holes are formed under gravitational collapse. Furthermore, there is a clear picture about how black holes can result from high energy collisions. However, this knowledge is based on the assumption that gravity is described exactly by general relativity, even at scales where we would naturally expect quantum gravity to take over. In addition, so far all (semi-)analytic studies of black hole formation processes are unrealistic in the sense that they adopt, at best, perfect fluids to describe the matter involved. This project proposes to take studies of gravitational collapse and shock wave collisions to the next level. On the one hand, 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. On the other hand, we will also study the effect of higher curvature corrections to general relativity on critical collapse. 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. Thus, while the research program is tailored to improve our present knowledge concerning black hole formation, it has also important implications for beyond-standard model physics and cosmology.