Recently, the ideas of extra dimensions and brane world scenarios have captured considerable interest. The potential ability of these brane-based models to explain the gauge hierarchy problem and the cosmological constant problem has been examined in numerous recent papers (on these subjects). In the first part of this thesis we examine many aspects of warped brane world scenarios, focusing on the Randall-Sundrum model. We begin with the stability issue of the Randall-Sundrum model and its cosmological implications. We will specifically verify that the Randall-Sundrum scenario; once stabilized, will reproduce the late-time conventional cosmology. In further studies, the possibility of providing a very small cosmological constant, in accordance with recent observations, is examined in the context of the warped brane world scenario. We also show that the "self-tuning" mechanism of the cosmological constant problem does not improve in the brane world models and the unnatural fine-tuning mystery of the cosmological constant problem remains unexplained. In the second part of this thesis some cosmological implications of the tachyon are examined. In particular, a mechanism is presented to take advantage of a time-varying tachyonic background to convert the energy of the tachyon to radiation at the end of inflation.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.82871 |
| Date | January 2003 |
| Creators | Firouzjahi, Hassan |
| Contributors | Cline, J. M. (advisor), Grisaru, M. (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Physics.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001982854, proquestno: AAINQ88466, Theses scanned by UMI/ProQuest. |
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