Speaker
Description
Resolving spacetime singularities within an effective classical description has motivated two complementary approaches. One is based on nonlocal gravities, which are able to smear localized matter sources over finite regions. The other is based on infinite towers of higher-curvature corrections to the Einstein--Hilbert action belonging to the Quasitopological class, which have recently been shown to possess vacuum regular black holes (RBHs) as their unique spherically symmetric solutions. Within these models, such RBHs arise from gravitational collapse, although singular matter distributions can still produce singular geometries. In this talk, I will review the features and shortcomings of both approaches. I will then combine them by presenting new nonlocal completions of Quasitopological gravities that admit exact, spherically symmetric vacuum RBHs, satisfy a perturbative Birkhoff theorem, and overcome several of the limitations of the individual frameworks.