Cosmic acceleration and the coincidence problem

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dc.contributor.advisorBassett, Bruceen_ZA
dc.contributor.authorKubwimana, Jean Claudeen_ZA
dc.date.accessioned2014-08-13T13:57:59Z
dc.date.available2014-08-13T13:57:59Z
dc.date.issued2009en_ZA
dc.descriptionIncludes abstract.en_ZA
dc.descriptionIncludes bibliographical references (leaves 83-89).en_ZA
dc.description.abstractIn the standard model of the Universe, the cosmos has only accelerated once since decoupling and only recently, at around a redshift of z ̃ 0.5 as supported by different observations including Type Ia Supernovae (SNIa), the Cosmic Microwave Background (CMB), Large Scale Structure (LSS), and Weak Lensing (WL). This confirmation however, lacks a fundamental physics explanation. The hypothetical form of energy termed 'dark energy' (DE) assumed to account for that acceleration behavior, is still mysterious and why its dominance only occurred recently is a profound problem widely known as the coincidence problem. So far all attempts for resolving the coincidence the problem have been unsatisfactory. Here we investigate a possible solution to the coincidence problem in the form of multiples phases of acceleration (MPA). If there were more than one phase of acceleration between now and decoupling, then the current phase of acceleration would be much less special, alleviating the coincidence problem. We use a modified Markov Chain Monte Carlo (MCMC) technique together with the WMAP five year TT data to search for parameters allowing a second phase of acceleration. Despite extensive search we find no models that simultaneously fit the WMAP data and yield a second phase of acceleration, ruling out this particular set of models as the solution to the coincidence problem.en_ZA
dc.identifier.apacitationKubwimana, J. C. (2009). <i>Cosmic acceleration and the coincidence problem</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Astronomy. Retrieved from http://hdl.handle.net/11427/6102en_ZA
dc.identifier.chicagocitationKubwimana, Jean Claude. <i>"Cosmic acceleration and the coincidence problem."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Astronomy, 2009. http://hdl.handle.net/11427/6102en_ZA
dc.identifier.citationKubwimana, J. 2009. Cosmic acceleration and the coincidence problem. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Kubwimana, Jean Claude AB - In the standard model of the Universe, the cosmos has only accelerated once since decoupling and only recently, at around a redshift of z ̃ 0.5 as supported by different observations including Type Ia Supernovae (SNIa), the Cosmic Microwave Background (CMB), Large Scale Structure (LSS), and Weak Lensing (WL). This confirmation however, lacks a fundamental physics explanation. The hypothetical form of energy termed 'dark energy' (DE) assumed to account for that acceleration behavior, is still mysterious and why its dominance only occurred recently is a profound problem widely known as the coincidence problem. So far all attempts for resolving the coincidence the problem have been unsatisfactory. Here we investigate a possible solution to the coincidence problem in the form of multiples phases of acceleration (MPA). If there were more than one phase of acceleration between now and decoupling, then the current phase of acceleration would be much less special, alleviating the coincidence problem. We use a modified Markov Chain Monte Carlo (MCMC) technique together with the WMAP five year TT data to search for parameters allowing a second phase of acceleration. Despite extensive search we find no models that simultaneously fit the WMAP data and yield a second phase of acceleration, ruling out this particular set of models as the solution to the coincidence problem. DA - 2009 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2009 T1 - Cosmic acceleration and the coincidence problem TI - Cosmic acceleration and the coincidence problem UR - http://hdl.handle.net/11427/6102 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/6102
dc.identifier.vancouvercitationKubwimana JC. Cosmic acceleration and the coincidence problem. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Astronomy, 2009 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/6102en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Astronomyen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherAstrophysics and Space Scienceen_ZA
dc.titleCosmic acceleration and the coincidence problemen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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