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Études on fuzzy geometry and cosmology

We investigate various aspects of noncommutative geometry and fuzzy field theory and their relations to string theory. In particular, we study the BPS and non-BPS solutions of the CJPN nonlinear sigma model on the noncommutative plane in some detail and show among other things that a class of its so...

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Main Author: Murugan, Jeffrey
Other Authors: Ellis, George F R
Format: Thesis
Language:English
Published: Department of Mathematics and Applied Mathematics 2016
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access_status_str Open Access
author Murugan, Jeffrey
author2 Ellis, George F R
author_browse Ellis, George F R
Murugan, Jeffrey
author_facet Ellis, George F R
Murugan, Jeffrey
author_sort Murugan, Jeffrey
collection Thesis
description We investigate various aspects of noncommutative geometry and fuzzy field theory and their relations to string theory. In particular, we study the BPS and non-BPS solutions of the CJPN nonlinear sigma model on the noncommutative plane in some detail and show among other things that a class of its solitonic excitations may be built from bound states of noncommutative scalar solitons. We then go on to construct a fuzzy extension of the semilocal SU(N)a x U(l)L Yang-Mills-Riggs model. We find that not only does this noncommutative model support a large class of BPS vortex solutions but, unlike in the commutative model, these are exact solutions of the BPS equations. We also study the large coupling limit of the semilocal model and demonstrate conclusively the metamorphosis of the semilocal vortex to an appropriate degree instanton of the fuzzy CJPN model. In the second part of this work, we study the perpendicular intersection of Dl- and D7-branes in type liB string theory and the fuzzy 6-sphere that resolves the singularity of the intersection. We demonstrate the equivalence of the D7 and dual D-string descriptions by computing the energy, charge and radial profiles of the solution in each description. We conclude the thesis with a foray into cosmology by constructing a realisation of a recently proposed singularity-free inflating universe. We discuss the basic characteristics of this model and show that none are at odds with current observations.
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publishDate 2016
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spelling oai:open.uct.ac.za:11427/19023 Études on fuzzy geometry and cosmology Murugan, Jeffrey Ellis, George F R Applied Mathematics We investigate various aspects of noncommutative geometry and fuzzy field theory and their relations to string theory. In particular, we study the BPS and non-BPS solutions of the CJPN nonlinear sigma model on the noncommutative plane in some detail and show among other things that a class of its solitonic excitations may be built from bound states of noncommutative scalar solitons. We then go on to construct a fuzzy extension of the semilocal SU(N)a x U(l)L Yang-Mills-Riggs model. We find that not only does this noncommutative model support a large class of BPS vortex solutions but, unlike in the commutative model, these are exact solutions of the BPS equations. We also study the large coupling limit of the semilocal model and demonstrate conclusively the metamorphosis of the semilocal vortex to an appropriate degree instanton of the fuzzy CJPN model. In the second part of this work, we study the perpendicular intersection of Dl- and D7-branes in type liB string theory and the fuzzy 6-sphere that resolves the singularity of the intersection. We demonstrate the equivalence of the D7 and dual D-string descriptions by computing the energy, charge and radial profiles of the solution in each description. We conclude the thesis with a foray into cosmology by constructing a realisation of a recently proposed singularity-free inflating universe. We discuss the basic characteristics of this model and show that none are at odds with current observations. 2016-04-20T14:08:39Z 2016-04-20T14:08:39Z 2007 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/19023 eng application/pdf Department of Mathematics and Applied Mathematics Faculty of Science University of Cape Town
spellingShingle Applied Mathematics
Murugan, Jeffrey
Études on fuzzy geometry and cosmology
thesis_degree_str Doctoral
title Études on fuzzy geometry and cosmology
title_full Études on fuzzy geometry and cosmology
title_fullStr Études on fuzzy geometry and cosmology
title_full_unstemmed Études on fuzzy geometry and cosmology
title_short Études on fuzzy geometry and cosmology
title_sort etudes on fuzzy geometry and cosmology
topic Applied Mathematics
url http://hdl.handle.net/11427/19023
work_keys_str_mv AT muruganjeffrey etudesonfuzzygeometryandcosmology