(Non)-singular brane-world cosmology induced by quantum effects in d5 dilatonic gravity

TL;DR

This paper explores how quantum effects in five-dimensional dilatonic gravity induce various brane-world cosmologies, including singular and non-singular models with dynamically determined brane and dilaton properties, within the framework of AdS/CFT correspondence.

Contribution

It presents new solutions for dilatonic brane-worlds influenced by quantum matter effects, including a non-singular model with dynamically determined brane radius and dilaton.

Findings

Quantum effects can induce inflationary brane-worlds.

Non-singular dilatonic brane-worlds are possible with fine-tuned potentials.

Similar brane-world behaviors occur with dilaton-coupled spinor matter.

Abstract

5d dilatonic gravity (bosonic sector of gauged supergravity) with non-trivial bulk potential and with surface terms (boundary cosmological constant and trace anomaly induced effective action for brane quantum matter) is considered. For constant bulk potential and maximally SUSY Yang-Mills theory (CFT living on the brane) the inflationary brane-world is constructed. The bulk is singular asymptotically AdS space with non-constant dilaton and dilatonic de Sitter or hyperbolic brane is induced by quantum matter effects. At the same time, dilaton on the brane is determined dynamically. This all is natural realization of warped compactification in AdS/CFT correspondence. For fine-tuned toy example of non-constant bulk potential we found the non-singular dilatonic brane-world where bulk again represents asymptotically AdS space and de Sitter brane (inflationary phase of observable Universe) is induced exclusively by quantum effects. The radius of the brane and dilaton are determined dynamically. The analytically solvable example of exponential bulk potential leading to singular asymptotically AdS dilatonic bulk space with de Sitter (or hyperbolic) brane is also presented.In all cases under discussion the gravity on the brane is trapped via Randall-Sundrum scenario. It is shown that qualitatively the same types of brane-worlds occur when quantum brane matter is described by $N$ dilaton coupled spinors.