eprintid: 32924
rev_number: 13
eprint_status: archive
userid: 7243
dir: disk0/00/03/29/24
datestamp: 2023-02-28 07:33:20
lastmod: 2023-03-14 08:36:03
status_changed: 2023-02-28 07:33:20
type: doctoralThesis
metadata_visibility: show
creators_name: Mikheev, Aleksandr N.
title: Far-from-equilibrium universal scaling dynamics in ultracold atomic systems and heavy-ion collisions
subjects: ddc-530
divisions: i-130700
adv_faculty: af-13
abstract: Classification and understanding of scaling solutions in closed quantum systems far from thermal equilibrium, known as nonthermal fixed points, are one of the open problems in
nonequilibrium quantum many-body theory. The usual method involves searching for possible self-similar solutions to a (nonperturbative) evolution equation, e.g., Boltzmann or
Kadanoff–Baym, starting from a far-from-equilibrium initial condition. In this work, we develop an alternative approach based on the correspondence between scaling and fixed points of the renormalization group. Using an ultracold Bose gas as an example we show how possible far-from-equilibrium scaling solutions can be systematically obtained by solving fixed-point renormalization-group equations. In the second part of this thesis, we investigate dynamics preceding a fully developed self-similar evolution. We use the Hamiltonian
formulation of kinetic theory to perform a stability analysis of nonthermal fixed points in an expanding non-Abelian plasma characterized by the Fokker–Planck collision kernel. Employing an adiabatic expansion we develop a perturbation theory, which at next-to-leading order allows us to derive stability equations for scaling exponents and obtain the Lyapunov relaxation rates associated with a nonthermal fixed point.
date: 2023
id_scheme: DOI
id_number: 10.11588/heidok.00032924
ppn_swb: 1837818827
own_urn: urn:nbn:de:bsz:16-heidok-329245
date_accepted: 2023-02-17
advisor: HASH(0x561a62886fe8)
language: eng
bibsort: MIKHEEVALEFARFROMEQU20230217
full_text_status: public
place_of_pub: Heidelberg
citation:   Mikheev, Aleksandr N.  (2023) Far-from-equilibrium universal scaling dynamics in ultracold atomic systems and heavy-ion collisions.  [Dissertation]     
document_url: https://archiv.ub.uni-heidelberg.de/volltextserver/32924/1/dissertation.pdf