Phase transition of AdS Schwarzschild black hole and gauge theory dual in presence of external string cloud

Abstract

We study the thermodynamics of AdS-Schwarzschild black hole in the presence of an external string cloud. We observe that, at any temperature, the black hole configuration is stable with non-zero entropy. We further notice that, when the value of the curvature constant equals to one, if the string cloud density has less than a critical value, within a certain range of temperature three black holes configuration exist. One of these black holes is unstable and other two are stable. At a critical temperature, a transition between these two stable black holes takes place which leads us to conclude that the bound state of quark and anti-quark pairs may not exist. By studying the corresponding dual gauge theory we confirm that the instability of the bound state of quark and anti-quark pair in the dual gauge theory.