Brane gravity, massless bulk scalar and self-tuning of the cosmological constant

Abstract

We show that a self-tuning mechanism of the cosmological constant could work in 5D non-compact space-time with a $Z_2$ 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 non-compact extra dimension. With a general form of 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.

1+15 pages, no figure, Version to appear in PRD

References in corpus (12)

• Strong Interactions and Stability in the DGP Model
• Non-Local Modification of Gravity and the Cosmological Constant Problem
• Selftuning and its footprints
• Avoidance of Naked Singularities in Dilatonic Brane World Scenarios with a Gauss-Bonnet Term
• Softly Massive Gravity
• Blown-up p-Branes and the Cosmological Constant
• Inflationary Cosmology with Five Dimensional SO(10)
• GUT Scale And Leptogenesis From 5D Inflation
• Einstein Gravity on a Brane in 5D Non-compact Flat Spacetime -DGP model revisited-
• Exit from inflation and a paradigm for vanishing cosmological constant in self-tuning models
• Diluting solutions of the cosmological constant problem
• Brane world in a texture

Cited by in corpus (8)

• Brane solutions of a spherical sigma model in six dimensions
• Einstein Gravity on a Brane in 5D Non-compact Flat Spacetime -DGP model revisited-
• The role of higher derivative bulk scalar in stabilizing a warped spacetime
• Inflation and Leptogenesis in Five Dimensional SO(10)
• Vacuum Polarization in an Anti-de Sitter Space as an Origin for a Cosmological Constant in a Brane World
• The nature of cosmological singularities in isotropic universes and braneworlds
• Toward solving the cosmological constant problem by embedding
• Self-tuning of the cosmological constant and Einstein Gravity on the brane