Dilatonic Repulsons and Confinement via the AdS/CFT Correspondence

TL;DR

This paper investigates dilatonic deformations of AdS_5 x S^5 geometry that exhibit confinement and repulsive naked singularities, proposing causality bounds as criteria for their physical relevance in the AdS/CFT framework.

Contribution

It introduces a class of non-supersymmetric dilatonic solutions with naked singularities that can still be physically meaningful, and derives exact QCD string tensions within this setup.

Findings

Confinement is observed in certain parameter ranges.

Naked singularities can be cloaked by repulsive effects.

Exact QCD string tension expressions are obtained.

Abstract

We study a class of dilatonic deformations of asymptotically AdS_5 X S^5 geometry analytically and numerically. The spacetime is non-supersymmetric and suffers from a naked singularity. We propose that the causality bound may serve as a criterion for such a geometry with a naked singularity to still make sense in the AdS/CFT correspondence. We show that the static string, the one corresponding to a large Wilson loop in the dual gauge theory, reveals confinement in a certain range of parameters of our solutions, where the singularity exhibits the repulsion that can well cloak the singularity from the static string probe. In particular, we find the exact expression for the tension of the QCD strings. We also discuss a possible interpretation of our solution in terms of unstable branes and their tachyon matter.