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Cosmic acceleration and the coincidence problem
Includes abstract.
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| Main Author: | |
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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Department of Astronomy
2014
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| _version_ | 1867613709206028288 |
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| access_status_str | Open Access |
| author | Kubwimana, Jean Claude |
| author2 | Bassett, Bruce |
| author_browse | Bassett, Bruce Kubwimana, Jean Claude |
| author_facet | Bassett, Bruce Kubwimana, Jean Claude |
| author_sort | Kubwimana, Jean Claude |
| collection | Thesis |
| description | Includes abstract. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/6102 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:40:27.438Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | Department of Astronomy |
| publisherStr | Department of Astronomy |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/6102 Cosmic acceleration and the coincidence problem Kubwimana, Jean Claude Bassett, Bruce Astrophysics and Space Science Includes abstract. Includes bibliographical references (leaves 83-89). 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. 2014-08-13T13:57:59Z 2014-08-13T13:57:59Z 2009 Master Thesis Masters MSc http://hdl.handle.net/11427/6102 eng application/pdf Department of Astronomy Faculty of Science University of Cape Town |
| spellingShingle | Astrophysics and Space Science Kubwimana, Jean Claude Cosmic acceleration and the coincidence problem |
| thesis_degree_str | Master's |
| title | Cosmic acceleration and the coincidence problem |
| title_full | Cosmic acceleration and the coincidence problem |
| title_fullStr | Cosmic acceleration and the coincidence problem |
| title_full_unstemmed | Cosmic acceleration and the coincidence problem |
| title_short | Cosmic acceleration and the coincidence problem |
| title_sort | cosmic acceleration and the coincidence problem |
| topic | Astrophysics and Space Science |
| url | http://hdl.handle.net/11427/6102 |
| work_keys_str_mv | AT kubwimanajeanclaude cosmicaccelerationandthecoincidenceproblem |