Magnetic Catalysis and Holography

Abstract

In this thesis we will study the effects of a magnetic field on the quark condensate. To do this we'll look at Quantum Chromo Dynamics, the breaking of chiral symmetry and the formation of the chiral condensate and how the magnetic field affects this. We'll discuss two different models, first the Improved Holographic QCD model with an added flavour sector, and the AdS-soliton model. While we could show a constructive effect of the magnetic field on the quark condensate in the soliton model, this proved to be out of our reach in the IHQCD theory due to the inability to get the proper tachyon divergence.