Nahum Critical Phenomena in Loop Models

2015
ISBN: 978-3-319-06407-9
Verlag: Springer International Publishing
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 141 Seiten, eBook

Reihe: Springer Theses

When close to a continuous phase transition, many physical systems can usefully be mapped to ensembles of fluctuating loops, which might represent for example polymer rings, or line defects in a lattice magnet, or worldlines of quantum particles. 'Loop models' provide a unifying geometric language for problems of this kind. This thesis aims to extend this language in two directions. The first part of the thesis tackles ensembles of loops in three dimensions, and relates them to the statistical properties of line defects in disordered media and to critical phenomena in two-dimensional quantum magnets. The second part concerns two-dimensional loop models that lie outside the standard paradigms: new types of critical point are found, and new results given for the universal properties of polymer collapse transitions in two dimensions. All of these problems are shown to be related to sigma models on complex or real projective space, CP^{n-1} or RP^{n-1} -- in some cases in a 'replica' limit -- and this thesis is also an in-depth investigation of critical behaviour in these field theories.

Zielgruppe

Research

Autoren/Hrsg.

Nahum, Adam

Inhaltsverzeichnis

Introduction.- Completely Packed Loop Models.- Topological Terms, Quantum Magnets and Deconfined Criticality.- The Statistics of Vortex Lines.- Loop Models with Crossings in 2D.- Polymer Collapse.- Outlook.- Appendix A Potts domain walls and CP^{n-1}.- Appendix B Phases for Hedgehogs & Vortices.