Since 2015, the LIGO-Virgo-KAGRA Collaboration has detected 90 signals from merging compact objects such as black holes and neutron stars. Each of these is analyzed using Bayesian inference, employing a stochastic algorithm such as Markov Chain Monte Carlo to compare data against models—thereby characterizing the source.
The detection of gravitational waves is a powerful tool in our quest to deepen our understanding of fundamental physics. To make the most out of this tool, we need to accurately simulate the whole process of gravitational wave emission, propagation and detection by interferometers.
Gravitational waves carry unique information about the compact objects that generate them and the underlying gravitational theory describing them, which has allowed us to test General Relativity and the nature of black holes with unprecedented precision. In addition, they can also bear precious information about the astrophysical environments where binaries coalesce.
Analytical predictions of the gravitational waveform (amplitude and phasing) are key ingredients for building the templates used in gravitational detectors.
We use physics-informed neural networks (PINNs) to compute the first quasi-normal modes of the Kerr geometry via the Teukolsky equation. This technique allows us to extract the complex frequencies and separation constants of the equation without the need for sophisticated numerical techniques, and with an almost immediate implementation under the \texttt{PyTorch} framework.
The NewFunFiCO Staff Exchange network had its kick off meeting on January 19th 2023. The meeting was virtual, but it promised very interesting real work and synergies to come in the next four years!
Asymmetric binaries provide a unique phenomenology within the family-tree of coalescing systems, which makes them golden targets for future gravitational wave interferometers. Assembled by a compact object orbiting around a more massive body, they can emit gravitational waves from the milliHz to the Hz regime, depending on the size of their components.
New horizon-scale images of the Galactic Center black hole Sagittarius A* (Sgr A*) recently published by the Event Horizon Telescope (EHT) allow for new strong-field tests of the Kerr metric in a previously unexplored regime. I will discuss the recent EHT observations of Sgr A* with a particular focus on how these new results can be used to test fundamental physics.
The idea that the Planck length can act as a regulator of UV divergences has inspired various approaches to quantum gravity, but a possibly much larger width for the ground state emerges in the (non-perturbative) quantisation of the Oppenheimer-Snyder model of dust collapse that naturally recovers Bekenstein’s area law.
It is well known that a classical charged scalar field on Reissner-Nordström spacetime undergoes superradiant scattering. By quantising the field, via canonical quantisation, we investigate the subtleties that superradiant scattering presents in the quantisation of the field.
Our group coordinated the "Numerical Relativity and High Energy Physics" IRSES network (2012-2015). Here is a list of the global network meetings organized:
