by
Ilia Musco(Laboratoire Univers et Théories (LUTH), Observatoire de Paris)
→
Europe/Rome
Aula Conversi (Dipartimento di Fisica - Ed. G.Marconi)
Aula Conversi
Dipartimento di Fisica - Ed. G.Marconi
Description
LECTURE: Gravitational Collapse
Abstract: In this lecture I will give a review of the gravitational collapse mechanism in
relativistic hydrodynamics assuming spherical symmetry, presenting the set of non linear
Einstein/fluid equations that need to be solved, focusing on perfect fluids. The equation of
state plays an important role to determine the outcome of the collapse. I will then discuss
the concept of space time foliation presenting the set of equations in two specific cases:
the Misner-Sharp comoving observer (cosmic time) and the Misner-Hernandez null
observer (observer time). The observer time foliation is particularly relevant for studying
black hole formation, following the complete evolution of the black hole exterior. I will
conclude introducing the concept of dynamical horizons for black holes in spherical
symmetry, generalizing the well known Schwarzschild condition R = 2M for the event
horizon.
SEMINAR: Primordial Black Hole Formation
Abstract: In the first part I will review the mechanism of gravitational collapse in
relativistic hydrodynamics assuming spherical symmetry, focusing on perfect fluids. With
the aim of studying black hole formation in different contexts, I will introduce the concept of
dynamical horizons, generalizing the Schwarzschild condition R = 2M for the event
horizon. In the second part I will present my results on primordial black hole formation,
using a Lagrangian relativistic hydrodynamical code to study the collapse of cosmological
perturbations in the early universe. They are interesting candidates for the dark matter
component of the Universe as well as for the seeds of supermassive black holes that we
observe today in the centres of galaxies.
