2002/08/31 by Yuri Shtanov, Varun Sahni · 1 citation
Physics and Astronomy · #Black Holes and Theoretical Physics #Brane #Classical mechanics #Cosmology and Gravitation Theories #Curvature #De Sitter universe #Friedmann–Lemaître–Robertson–Walker metric #Galaxies: Formation, Evolution, Phenomena #Geometry #Initial singularity #Mathematical physics #Physics #Quantum mechanics #Singularity #Tensor (intrinsic definition) #Theoretical physics #Universe #astro-ph #gr-qc #hep-ph #hep-th
paper · pdf · doi:10.1016/s0370-2693(03)00179-5
published as Phys.Lett.B557:1-6,2003 · 9 pages, 1 figure, revtex, accepted for publication in Phys. Lett. B
arxiv created 2003/02/09 · openalex publication_date 2003/03/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We study cosmological braneworld models with a single timelike extra dimension. Such models admit the intriguing possibility that a contracting braneworld experiences a natural bounce without ever reaching a singular state. This feature persists in the case of anisotropic braneworlds under some additional and not very restrictive assumptions. Generalizing our study to braneworld models containing an induced brane curvature term, we find that a FRW-type singularity is once again absent if the bulk extra dimension is timelike. In this case, the universe either has a non-singular origin or commences its expansion from a quasi-singular state during which both the Hubble parameter and the energy density and pressure remain finite while the curvature tensor diverges. The non-singular and quasi-singular behaviour which we have discovered differs both qualitatively and quantitatively from what is usually observed in braneworld models with spacelike extra dimensions and could have interesting cosmological implications.