2003/05/31 by Jihn E. Kim, Bumseok Kyae, Qaisar Shafi
Physics and Astronomy · #Black Holes and Theoretical Physics #Cosmology and Gravitation Theories #Noncommutative and Quantum Gravity Theories #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.70.064039
published as Phys.Rev.D70:064039,2004 · 1+15 pages, no figure, Version to appear in PRD
arxiv created 2004/07/26 · openalex publication_date 2004/09/30 · arxiv updated 2011/05/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We show that a self-tuning mechanism of the cosmological constant could work in 5D noncompact space-time with a Z2 symmetry in the presence of a massless scalar field. The standard model matter fields live only on the 4D brane. The change of vacuum energy on the brane (brane cosmological constant) by, for instance, electroweak and QCD phase transitions, just gives rise to dynamical shifts of the profiles of the background metric and the scalar field in the extra dimension, keeping 4D space-time flat without any fine-tuning. To avoid naked singularities in the bulk, the brane cosmological constant should be negative. We introduce an additional brane-localized 4D Einstein-Hilbert term so as to provide the observed 4D gravity with the noncompact extra dimension. With a general form of the brane-localized gravity term allowed by the symmetries, the low energy Einstein gravity is successfully reproduced on the brane at long distances. We show this phenomenon explicitly for the case of vanishing bulk cosmological constant.