Branes on Charged Dilatonic Backgrounds: Self-Tuning, Lorentz Violations and Cosmology

TL;DR

This paper constructs charged dilatonic brane backgrounds with various geometries, exploring their implications for self-tuning, Lorentz violations, and cosmological models, including black branes and cosmological regions.

Contribution

It introduces new charged dilatonic backgrounds with asymmetric warping that connect scalar self-tuning solutions to black hole geometries, addressing singularity issues and Lorentz symmetry breaking.

Findings

Charged dilatonic backgrounds with black brane and cosmological regions.

Asymmetrically warped geometries break Lorentz symmetry in a controlled way.

Potential implications for cosmology and particle physics.

Abstract

We construct an n+q+2 dimensional background that has dilatonic q-brane singularities and that is charged under an antisymmetric tensor field, the background spacetime being maximally symmetric in n-dimensions with constant curvature k=0,+1,-1. For k=1 the bulk solutions correspond to black q-branes. For k=0,-1 the geometry resembles the `white hole' region of the Reissner-N"ordstrom solution with a past Cauchy horizon. The metric between the (timelike) singularity and the horizon is static whereas beyond the horizon it is cosmological. In the particular case of q=0, we study the motion of a codimension one n-brane in these charged dilatonic backgrounds that interpolate between the original scalar self-tuning and the black hole geometry and provide a way to avoid the naked singularity problem and/or the need of having exotic matter on the brane. These backgrounds are asymmetrically warped and so break 4D Lorentz symmetry in a way that is safe for particle physics but may lead to faster than light propagation in the gravitational sector.