Strong Gravity News & Events

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.

Resonances are ubiquitous in nature. In this talk, I will focus on resonances due to the interaction of two black holes orbiting a central massive black hole. Such tidal resonances will generically occur for Extreme Mass Ratio Inspirals (EMRIs), if nearby compact objects exist.