Bouncing and cyclic universes in the charged AdS bulk background

TL;DR

This paper investigates bouncing and cyclic universes within a charged AdS bulk using brane-world models, exploring different approaches and conditions to avoid exotic matter and examining implications for holography and Lorentz invariance.

Contribution

It compares the moving domain wall and BDL approaches in charged AdS backgrounds, proposing methods to avoid exotic matter and analyzing the role of holographic matter and Lorentz invariance.

Findings

Bouncing universes occur for flat and open geometries without exotic matter.

Cyclic universe solutions are found for closed geometries with exotic stiff matter.

Introducing local matter can eliminate the need for exotic matter on the brane.

Abstract

We study bouncing and cyclic universes from an (n+1)-dimensional brane in the (n+2)-dimensional charged AdS bulk background. In the moving domain wall (MDW) approach this picture is clearly realized with a specified bulk configuration, the 5D charged topological AdS (CTAdS_5) black hole with mass M and charge Q. The bulk gravitational dynamics induces the 4D Friedmann equations with CFT-radiation and exotic stiff matters for a dynamic brane. This provides bouncing universes for k=0, -1 and cyclic universe for k=1, even though it has an exotic stiff matter from the charge Q. In this work we use the other of the Binetruy-Deffayet-Langlos (BDL) approach with the bulk Maxwell field. In this case we are free to determine the corresponding mass M-tilde and charge Q-tilde because the mass term is usually included as an initial condition and the charge is given by an unspecified solution to the Maxwell equation under the BDL metric. Here we obtain only bouncing universes if one does not choose two CTAdS_5 black holes as the bulk spacetime. We provide a way of avoiding the exotic matter on the brane by introducing an appropriate local matter. Finally we discuss an important relation between the exotic holographic matter and Lorentz invariance violation.