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A study of integrability conditions for irrotational dust spacetimes

Bibliography: pages 139-145.

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Bibliographic Details
Main Author: Lesame, William Mphepeng
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 Lesame, William Mphepeng
author2 Ellis, George F R
author_browse Ellis, George F R
Lesame, William Mphepeng
author_facet Ellis, George F R
Lesame, William Mphepeng
author_sort Lesame, William Mphepeng
collection Thesis
description Bibliography: pages 139-145.
format Thesis
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institution University of Cape Town (South Africa)
language eng
last_indexed 2026-06-10T12:34:25.395Z
license_str Not specified — see source repository
provenance_str_mv Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository
publishDate 2016
publishDateRange 2016
publishDateSort 2016
publisher Department of Mathematics and Applied Mathematics
publisherStr Department of Mathematics and Applied Mathematics
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source_str UCTD — University of Cape Town Open Access Repository
spelling oai:open.uct.ac.za:11427/21328 A study of integrability conditions for irrotational dust spacetimes Lesame, William Mphepeng Ellis, George F R Mathematics and Applied Mathematics Bibliography: pages 139-145. This thesis examines consistency conditions for fluid solutions of the field equations of general relativity. The exact non-linear dynamic equations for a generic irrotational dust spacetime are consistent. To analyse conditions characterizing pure gravity waves, linearization instability in general relativity and consistency of the so-called "silent universes", further exact conditions are imposed locally on irrotational dust. These are classified into Class II conditions, which change evolution equations into constraint equations, and Class I and III conditions, which do not doso-rather they add a new constraint, leaving the propagation equations unchanged in form. Class I conditions are imposed on terms in the constraint equations, while Class II and III conditions are imposed on terms in the evolution equations. In the Class I case it is shown that for irrotational dust space times the divergence-free magnetic Weyl tensor and the divergence-free electric Weyl tensor (necessary conditions for gravity waves interacting with matter), both imply integrability conditions in the exact non-linear case. The integrability conditions for the divergence-free magnetic Weyl tensor are identically satisfied in the linearized perturbation case, but are non-trivial in the exact non-linear case. This leads to a linearization instability in these models. The integrability conditions for the divergence-free electric Weyltensor are non-trivial in both the linear and non-linear cases. The Class II case focuses on irrotational silent cosmological dust models characterized by vanishing magnetic Weyl tensor and vanishing electric Weyl tensor. In both these models there exist a series of integrability conditions that need to be satisfied. Integrability conditions for the zero magnetic Weyl tensor condition hold identically for linearized case, but are non-trivial in the exact non-linear case. Thus there is also a linearization instability. The zero electric Weyl tensor condition leads to a chain of non-trivial integrability conditions in both the linear and non-linear cases. Because of the complexity of the integrability conditions, it is highly unlikely that there is a large class of models in both the silent zero magnetic Weyl tensor case and the silent zero electric Weyl tensor case. 2016-08-18T13:51:02Z 2016-08-18T13:51:02Z 1998 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/21328 eng application/pdf Department of Mathematics and Applied Mathematics Faculty of Science University of Cape Town
spellingShingle Mathematics and Applied Mathematics
Lesame, William Mphepeng
A study of integrability conditions for irrotational dust spacetimes
thesis_degree_str Doctoral
title A study of integrability conditions for irrotational dust spacetimes
title_full A study of integrability conditions for irrotational dust spacetimes
title_fullStr A study of integrability conditions for irrotational dust spacetimes
title_full_unstemmed A study of integrability conditions for irrotational dust spacetimes
title_short A study of integrability conditions for irrotational dust spacetimes
title_sort study of integrability conditions for irrotational dust spacetimes
topic Mathematics and Applied Mathematics
url http://hdl.handle.net/11427/21328
work_keys_str_mv AT lesamewilliammphepeng astudyofintegrabilityconditionsforirrotationaldustspacetimes
AT lesamewilliammphepeng studyofintegrabilityconditionsforirrotationaldustspacetimes