Magnetic Catalysis in Holographic QCD

Abstract

In this thesis we study, by using the AdS/CFT correspondence, the formation of a chiral condensate and the subsequent dependence on an external magnetic field in large Nc QCD-like theories at finite tempera- ture. This was done via two gravity duals, the AdS-soliton model and the Improved Holographic QCD model to which a avour sector was added by introducing probe branes. In the case of the AdS-Soliton, a 6 dimensional model with one spatial dimension compactified on a circle, a constructive effect on the condensate was observed, a phenomenon coined "Magnetic Catalysis". The second model proved to be substantially more difficult, failing to give the desired chiral symmetry breaking solutions due to nu- merical errors. Therefore an extensive discussion and outlook will be given in order for future work to be able to overcome this problems.