title: Quantum Dynamics from the Functional Renormalisation Group with a Temporal Regulator
creator: Corell, Lukas
subject: ddc-500
subject: 500 Natural sciences and mathematics
subject: ddc-530
subject: 530 Physics
description: In this work, a framework for the computation of the time evolution of  correlation functions is developed. For that purpose, techniques from the  functional renormalisation group (fRG) are used, with the unique feature of a  temporal regulator. This specific choice of regulator suppresses quantum  fluctuations based on a time scale and yields causal properties for correlation  functions. As a consequence, flow equations can always be integrated  analytically, which in turn allows for the derivation of a one-loop exact  functional relation for the inverse propagator. In addition to this formal  result, the method is applied to the phi^3-theory, where the dynamics of the  propagator is investigated. In this setup, the system is prepared  far-from-equilibrium and the time evolution of the propagator is computed. Even  in the simple truncation that is employed, there are already hints at a  self-similar time evolution.    In a separate part, three-dimensional Yang-Mills theory is examined in  equilibrium. Due to the simpler computation as opposed to non-equilibrium  scenarios, it is possible to investigate this theory in view of different  truncations. This study reveals that truncations have to be chosen carefully in  order to achieve apparent convergence.
date: 2021
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/30183/1/corell_dissertation.pdf
identifier: DOI:10.11588/heidok.00030183
identifier: urn:nbn:de:bsz:16-heidok-301831
identifier:   Corell, Lukas  (2021) Quantum Dynamics from the Functional Renormalisation Group with a Temporal Regulator.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/30183/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng