2000/08/31 by A. Mennim, Andrew Mennim, Richard A. Battye +1 · 2 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1088/0264-9381/18/11/313
published as Class.Quant.Grav.18:2171-2194,2001 · 20 pages - Version to appear in Classical and Quantum Gravity. New section added on conformal rescaling of the metric. Some other minor changes made and references added
arxiv created 2001/04/17 · openalex publication_date 2001/05/16 · arxiv updated 2009/11/30 · openalex created_date 2020/11/23 · openalex updated_date 2026/07/28
We explore the nature of cosmological expansion induced by matter in a brane-world scenario with a bulk scalar field, such as a dliaton. We use a covariant formalism to obtain an expression for the effective 4D equations on the brane via projection, and hence deduce the expansion rate. We discuss in detail the effects of the bulk on the brane and how the scalar field can induce contributions to the expansion rate. These methods are applied to the Randall-Sundrum scenarios and to models suggested to stabilize the size of the extra-dimension using a scalar field, such as that due to Goldberger and Wise. We find that in such models the expansion rate is negative on a negative tension brane when the extra dimension is stabilized irrespective of whether there is a scalar field, contrary to some claims in the literature. The formalism can also be applied to cosmological applications of a Horava-Witten type model with and without a coupling between the scalar field and the matter on the brane. We compare and contrast these 'rolling-radius models' with 4D models in which fundamental constants vary. The coupling of the matter on thebrane to the scalar field appears to allow for the possibility of accelerated expansion on the brane driven by the effects of the bulk.