ELFT HÍRADÓ

[Bence Kocsis <bkocsis AT caesar.elte.hu>]

GALNUC Seminar

Tuesday, April 10, 2018, 4:00 p.m.
Eotvos Lagymanyos campus, Pazmany Peter s. 1/A, room 3.139

speaker:  Adam Takacs (ELTE)

*Phase Transitions in Galactic Nuclei*

The gravitational interaction among bodies orbiting in a spherical
potential leads to the rapid relaxation of the orbital planes'
distribution, a process called vector resonant relaxation. In this talk I
will discuss the Hamiltonian and the statistical equilibrium of this
process. The equilibrium distribution resembles a counterrotating disk at
low temperature and a spherical structure at high temperature. The system
exhibits a first order phase transition between the disk and the spherical
phase in the canonical ensemble if the total angular momentum is below a
critical value. We find that the phase transition erases the high order
multipoles, i.e. small-scale structure in angular momentum space, most
efficiently. The system admits a maximum entropy and a maximum energy,
which lead to the existence of negative temperature equilibria

Everyone is welcome!