When:
Tuesday, February 16, 2016
4:00 PM - 5:00 PM CT
Where: Technological Institute, F160, 2145 Sheridan Road, Evanston, IL 60208 map it
Audience: Faculty/Staff - Student - Public
Contact:
Monica Brown
(847) 491-7650
Group: Physics and Astronomy Astrophysics Seminars
Category: Academic
Title: Stellar Dynamics around a Massive Black Hole
Speaker: Ben Bar-Or, Institute for Advanced Study
Host: Fabio Antonini
Abstract: Galactic nuclei and the Massive black holes (MBHs) in their centers
are rich environments, where the complex stellar dynamics plays an
important role in many physical phenomena. We show that the standard
description of the two-body relaxation, around an MBH, as a diffusion
process, is incomplete. We derived a non-perturbative solution for
energy relaxation as an anomalous diffusion process, and a robust
estimation technique to measure it in N-body simulations. We also show
how the dynamics of a nearly-Keplerian N-body system, where the
angular momentum evolution is accelerated by resonant relaxation, can
be described and studied in a formal statistical mechanics
framework. In this framework the background potential is described as
a correlated Gaussian noise. We obtained the leading order,
phase-averaged stochastic equations of motion and derived an effective
Fokker-Plank equation for a general correlated Gaussian noise. We
combine the Fokker-Plank description of two-body relaxation and
resonant relaxation to study the loss-cone dynamics in Galactic
nuclei.
Keywords: Physics, Astronomy, Astrophysics