2005/12/31 by Paul McFadden, Neil Turok, Paul J. Steinhardt · 1 citation
Physics and Astronomy · #Astrophysics #Big Bang (financial markets) #Big Bounce #Big Crunch #Black Holes and Theoretical Physics #Boundary (topology) #Brane #Brane cosmology #Classical mechanics #Cosmology #Cosmology and Gravitation Theories #De Sitter universe #Galaxies: Formation, Evolution, Phenomena #Gravitational singularity #Initial singularity #Limit (mathematics) #Mathematical analysis #Perturbation (astronomy) #Physical cosmology #Physics #Quantum mechanics #Singularity #Theoretical physics #Ultimate fate of the universe #Universe #hep-th
paper · pdf · doi:10.1103/physrevd.76.104038
published as Phys.Rev.D76:104038,2007 · 54 pages, 12 figures, URL updated & 3 references added
arxiv created 2006/01/08 · openalex publication_date 2007/11/26 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We solve for the cosmological perturbations in a five-dimensional background consisting of two separating or colliding boundary branes, as an expansion in the collision speed V divided by the speed of light c. Our solution permits a detailed check of the validity of four-dimensional effective theory in the vicinity of the event corresponding to the big crunch/big bang singularity. We show that the four-dimensional description fails at the first nontrivial order in (V/c)2. At this order, there is nontrivial mixing of the two relevant four-dimensional perturbation modes (the growing and decaying modes) as the boundary branes move from the narrowly separated limit described by Kaluza-Klein theory to the well-separated limit where gravity is confined to the positive-tension brane. We comment on the cosmological significance of the result and compute other quantities of interest in five-dimensional cosmological scenarios.