Publication details for Dr Ian VernonVernon, Ian R. & Jennings, David. (2005). Graviton Emission into Non-Z_2 Symmetric Brane World Spacetimes. Journal of Cosmology and Astroparticle Physics 07: 011.
- Publication type: Journal papers: academic
- ISSN/ISBN: 1475-7516
- DOI: 10.1088/1475-7516/2005/07/011
- Keywords: extra-dimensions, early universe cosmology
- View online: Online version
- Durham research online: DRO record
Author(s) from Durham
The equations for the evolution of a homogeneous brane world that emits gravitons at early times, and into a non-Z_2 symmetric bulk, are derived using an AdS-Vaidya spacetime approximation. The behaviour of the black hole mass parameters either side of the brane is analysed, and it is found that in general graviton emission leads to a decrease in the non-Z_2 symmetry. However, the behaviour of the dark radiation term in the Friedmann equation is more complex: it is shown that this term can increase or decrease due to the non-Z_2 symmetry, and can become negative in some cases, leading to H=0 and the brane universe collapsing. Constraints on the initial (nonzero) sizes of the mass parameters are therefore derived.