Events

Building Regular Black Holes

Thu, 16 Apr 2026 11:00:06 +0000

Tuesday, 21st of April, 2026 from 3 p.m. to 5 p.m.

DF Seminar Room (2-8.3), 2nd floor of Physics Building

Regular, singularity-free black holes have been studied for more than sixty years as a possible resolution of the black hole singularity problem. Progress, however, has largely been focused on questions at the kinematical or phenomenological level, since no robust dynamical mechanism for their formation has yet been established. This is a central issue, as the viability of regular black holes ultimately depends on such dynamical considerations.

In this talk, I will argue that, if regular black holes play a role in resolving spacetime singularities, they may arise naturally from resummed higher-derivative corrections of the kind expected in quantum gravity.

I will discuss a recent explicit realization of this idea, survey the main results obtained so far in this framework, and highlight the major open problems that remain.

Event horizon termination and the emergence of Lorentz signature

Tue, 14 Apr 2026 09:29:57 +0000

Wednesday, 22nd of April, 2026 from 11 a.m. to 1 p.m.

DF Seminar Room (2-8.3), 2nd floor of Physics Building

In this talk, I describe in detail how one might understand the termination of the event horizon of a black hole in terms of of quasiregular singularity characterized by points possessing two futuredirected light cones and two past-directed light cones (in fact this spacetime is conformal to a region of the 1+1 trousers spacetime).

I then discuss Euclidean signature shift-symmetric scalartensor theories from which one can extract a Lorentzian structure, and show how this theory can provide a microscopic description for the aforementioned singularities. I discuss some recent works on the emergence of Lorentzian dispersion relations and a model for the big bang, as well as some preliminary and ongoing work on understanding compact objects in this class of theories.

Turbulence in Magnetised Neutron Stars

Tue, 21 Apr 2026 14:11:22 +0000

Thursday, 23rd of April, 2026 from 2:30 p.m. to 4 p.m.

DF Seminar Room (2-8.3), 2nd floor of Physics Building

The magnetic field configuration in the interior of Neutron Stars is an open problem and may be impacted by the influence of a turbulent cascade within the star. Turbulent magnetic fields also play a key role in the evolution of Binary Neutron Star (BNS) mergers, driving outflowing matter and launching ultrarelativistic jets.

Modelling turbulent flow with numerical simulations either requires incredibly high resolution simulations, or effective models to capture the impact of turbulence on large scales. In this talk I will firstly present a series of high resolution simulations of magnetised isolated neutron stars, to discuss the impact of the magnetic field on turbulent flow in the star interior, and the long term evolution of the magnetic field configuration.

I will then discuss the impact of the end state of this magnetic field configuration on a BNS merger, and demonstrate the construction of a subgrid model to effectively incorporate the …

Unfolding the Time Structure of Quantum Chromodynamics in Heavy-Ion Collisions

Thu, 09 Apr 2026 13:28:13 +0000

Wednesday, 29th of April, 2026 from 4 p.m. to 6 p.m.

Anfiteatro PA2 (Piso -1 do Pavilhão de Matemática) do IST

Ultra-relativistic heavy-ion collisions recreate, for fleeting instants, the hottest and densest conditions known in the Universe — a phase where quarks and gluons exist in a strongly-coupled state known as the Quark–Gluon Plasma (QGP). These environments, produced at facilities like the Large Hadron Collider (CERN) and the Relativistic Heavy Ion Collider (Brookhaven National Laboratory), allow us to reveal fundamental aspects of Quantum Chromodynamics (QCD), the theory of the strong interaction. Jets, collimated sprays of particles initiated by high-energy quarks or gluons, are among the most powerful probes, capable of traversing the evolving QGP and interacting with its constituents.

Traditionally studied in energy-momentum space and regarded as mathematical tools rather than physical entities, jets were long considered to be virtual constructs. Yet recent theoretical and phenomenological efforts have revealed that, in the presence of a medium, jets acquire real space-time features, a new physical layer that leave measurable imprints on experimental …