6 papers
Timelike convergence condition in regular black-hole spacetimes with (anti-)de Sitter core
Johanna Borissova, Stefano Liberati, Matt Visser
The Hawking-Penrose (1970) singularity theorem weakens the causality assumption of global hyperbolicity used in the Penrose (1965) singularity theorem, at the expense of invoking t…
From de Sitter to anti-de Sitter singularity regularization: Theory and phenomenology
Julio Arrechea, Stefano Liberati, Hooman Neshat +1
Recent investigations of vacuum polarization in extremely compact stars suggest that, in such regimes, the effective matter content of spacetime may acquire a vacuum-energy equatio…
Physical and Theoretical Challenges to Integrable Singularities
Julio Arrechea, Stefano Liberati, Hooman Neshat +1
Black hole spacetimes that exhibit integrable singularities have gained considerable interest as alternatives to both regular and singular black holes. Unlike most known regular bl…
Violations of the null convergence condition in kinematical transitions between singular and regular black holes, horizonless compact objects, and bounces
Johanna Borissova, Stefano Liberati, Matt Visser
How do regular black holes evade the Penrose singularity theorem? Various models of stationary regular black holes globally satisfy the null convergence condition (NCC). At first g…
Towards a Non-singular Paradigm of Black Hole Physics
Raúl Carballo-Rubio, Francesco Di Filippo, Stefano Liberati +18
The study of regular black holes and black hole mimickers as alternatives to standard black holes has recently gained significant attention, driven both by the need to extend gener…
Inner horizon instability via the trace anomaly effective action
Julio Arrechea, Giulio Neri, Stefano Liberati
In quantum field theory applied to black hole spacetimes, substantial evidence suggests that the Unruh and Hartle-Hawking vacuum states become singular at Cauchy horizons. This rai…