Moving Domain Walls in $AdS_5$ and Graceful Exit from Inflation

TL;DR

This paper explores moving branes in AdS_5 backgrounds within Randall-Sundrum models, proposing a brane scattering scenario that could explain a finite inflationary period and its graceful exit.

Contribution

It introduces solutions for moving branes with specific velocities and constructs multi-brane configurations without Z_2 symmetry, linking brane dynamics to inflationary scenarios.

Findings

Moving branes can have velocities determined by tension and cosmological constant.

Multi-brane configurations are possible without Z_2 symmetry by patching AdS-Schwarzschild solutions.

A brane scattering scenario can produce a finite period of inflation with a graceful exit.

Abstract

We consider moving-brane-solutions in AdS type back ground. In the first Randall-Sundrum configuration, there are two branes at fixed points of the orbifold symmetry. We point out that if one brane is fixed and the other brane is moving, the configuration is still a solution provided the moving brane has a specific velocity determined by its tension and bulk cosmological constant. In the absence of the $\bf Z_2$ symmetry, we can construct multi-brane configurations by patching AdS-Schwarzshild solutions. In this case, we show that the 4-dimensional effective cosmological constant on the brane world is not well defined. We find a condition for a brane to be stationary. Using the brane scattering, we suggest a scenario of inflation on the brane universe during a finite time, i.e, a scenario of a graceful exit of inflation.