Planck Stars and Spin Foam Transition Amplitudes

by Fabio D'Ambrosio (ETH Zurich)

Thursday 2 Apr 2020, 14:15 → 16:15 Europe/Berlin

Abbeanum SR 102

Classical general relativity predicts that a gravitationally
collapsed object is stable and singular: Once a trapping surface forms,
it is forever present in the spacetime and it hides a singularity from
our view. This picture might be drastically changed when
non-perturbative quantum gravity effects are included.
In the recently proposed Planck star model, insights from loop quantum
gravity are used to argue that black holes never form a singularity and
that they can turn into white holes. This tantalizing scenario provides
us with a test ground for various conceptual ideas and approaches to
quantum gravity since it gives rise to a well-defined observable that
can in principle be computed from any quantum theory of gravity. In this
talk I will give a qualitative introduction to the Planck star model and
discuss how it led to new insights into the computation of covariant
loop quantum gravity transition amplitudes.