Gravity seminar - Carlos Herdeiro Seminar

Abstract: The Kerr hypothesis is that astrophysical black hole candidates are very
special objects, with only two degrees of freedom and well described by
the Kerr metric. Theoretically, this hypothesis is based on the
uniqueness theorems for electro-vacuum. But in the presence of other
types of matter or modified gravity are there any viable alternatives?
In this talk I will illustrate some examples of black holes with "hair"
that could co-exist with Kerr black holes, but emerge dynamically (and
be preferred) at particular scales, either in General Relativity with
ultralight bosonic matter or in modified gravity with higher curvature
corrections, commenting on their theoretical and phenomenological
differences (e.g. shadows) and on their phenomenological viability. If
time permits I shall also illustrate a generic obstruction to black hole
mimickers that emerge from incomplete gravitational collapse.