2008/06/30 by Masato Minamitsuji · 4 citations
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #gr-qc #hep-th
paper · pdf · doi:10.1016/j.physletb.2010.01.010
published as Phys.Lett.B684:92-95,2010 · 4 pages, critical changes
arxiv created 2010/01/09 · openalex publication_date 2010/01/16 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/02
The self-accelerating branch of the Dvali–Gabadadze–Porrati (DGP) five-dimensional braneworld has provided a compelling model for the current cosmic acceleration. Recent observations, however, have not favored it so much. We discuss the solutions which contain a de Sitter 3-brane in the cascading DGP braneworld model, which is a kind of higher-dimensional generalizations of the DGP model, where a p-dimensional brane is placed on a (p+1)-dimensional one and the p-brane action contains the (p+1)-dimensional induced scalar curvature term. In the simplest six-dimensional model, we derive the solutions. Our solutions can be classified into two branches, which reduce to the self-accelerating and normal solutions in the limit of the original five-dimensional DGP model. In the presence of the six-dimensional bulk gravity, the ‘normal’ branch provides a new self-accelerating solution. The expansion rate of this new branch is generically lower than that of the original one, which may alleviate the fine-tuning problem.