The thermodynamics of rotating black hole clusters – Yuri Levin

The thermodynamics of rotating black hole clusters Yuri Levin Center for Computational Astrophysics, Flariton Institute Statistical physics has a bad track record in describing large-N gravitational systems. It has become clear over the last several years that there is a remarkable exception to this rule. Resonant relaxation due to orbit-averaged secular dynamics in galactic nuclei drives them to states of thermal and rotational equilibria on an astronomically short timescale. Statistical physics becomes a powerful, yet under-appreciated tool to study such systems. I will introduce the general formalism (due mostly to Touma and Tremaine, but going as far back as Lynden-Bell), as well as a novel numerical algorithm for finding equilibria due to Andrei Gruzinov. There are fun applications: phase transitions leading to lopsided precessing equilibria (such as the nucleus of Andromeda), and strong clustering in eccentricity and inclination of stellar-mass black holes. I will use statistical physics to argue that secular-dynamical friction must exist and that moreover, it plays a huge role in galactic nuclei, turning rotating clusters into flywheels that control the orbits of all heavy objects inside them, such as stellar discs and IMBHs. I will speculate on its effect on the spin of the supermassive black hole itself.

Horarios: En Junio 15, 2021

Publicado por: Patricia Tissera