Suppressing Discretization Error in Langevin Simulations of (2+1)-dimensional Field Theories

dc.contributor.authorWojtas, David Heinrichen
dc.date.accessioned2008-09-07T23:19:52Z
dc.date.available2008-09-07T23:19:52Z
dc.date.issued2006en
dc.description.abstractLattice simulations are a popular tool for studying the non-perturbative physics of nonlinear field theories. To perform accurate lattice simulations, a careful account of the discretization error is necessary. Spatial discretization error as a result of lattice spacing dependence in Langevin simulations of anisotropic (2 + 1)-dimensional classical scalar field theories is studied. A transfer integral operator (TIO) method and a one-loop renormalization (1LR) procedure are used to formulate effective potentials. The effective potentials contain counterterms which are intended to suppress the lattice spacing dependence. The two effective potentials were tested numerically in the case of a phi-4 model. A high accuracy modified Euler method was used to evolve a phenomenological Langevin equation. Large scale Langevin simulations were performed in parameter ranges determined to be appropriate. Attempts at extracting correlation lengths as a means of determining effectiveness of each method were not successful. Lattice sizes used in this study were not of a sufficient size to obtain an accurate representation of thermal equilibrium. As an alternative, the initial behaviour of the ensemble field average was observed. Results for the TIO method showed that it was successful at suppressing lattice spacing dependence in a mean field limit. Results for the 1LR method showed that it performed poorly.en
dc.identifier.urihttp://hdl.handle.net/10092/1294
dc.identifier.urihttp://dx.doi.org/10.26021/6296
dc.language.isoen
dc.publisherUniversity of Canterbury. Physics and Astronomyen
dc.relation.isreferencedbyNZCUen
dc.rightsCopyright David Heinrich Wojtasen
dc.rights.urihttps://canterbury.libguides.com/rights/thesesen
dc.subjectquantum field theoryen
dc.subjectLangevin simulationsen
dc.subjecttransfer matrixen
dc.subjectdiscretizationen
dc.titleSuppressing Discretization Error in Langevin Simulations of (2+1)-dimensional Field Theoriesen
dc.typeTheses / Dissertations
thesis.degree.disciplinePhysicsen
thesis.degree.grantorUniversity of Canterburyen
thesis.degree.levelMastersen
thesis.degree.nameMaster of Scienceen
uc.bibnumber1019946en
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