Supersymmetric plasma systems and their nonsupersymmetric counterparts

Abstract

In this thesis a systematic comparison of supersymmetric plasma systems and their nonsupersymmetric counterparts is presented. The work is motivated by the AdS/CFT correspondence and the main aim is to check how much the plasma governed by the N=4 super Yang-Mills theory resembles the quark-gluon plasma studied experimentally in relativistic heavy-ion collisions. The analysis is done in a weak coupling regime where perturbative methods are applicable. Since the Keldysh-Schwinger approach is used, not only equilibrium but also nonequilibrium plasmas, which are assumed to be ultrarelativistic, are under consideration. First, using the functional techniques we introduce Faddeev-Popov ghosts into the Keldysh-Schwinger formalism of nonAbelian gauge theories. Next the collective excitations of the N=1 SUSY QED plasma are considered and compared to those of the usual QED system. The analysis is repeated to confront with each other the plasmas governed by the N=4 super Yang-Mills and QCD theories. Finally, transport properties of the systems are also discussed. Since both collective excitations and transport characteristics of supersymmetric and nonsupersymmetric plasmas are very similar to each other we conclude that supersymmetric plasma systems are qualitatively the same as their nonsupersymmetric partners in weak coupling regime. The quantitative differences mostly reflect different numbers of degrees of freedom.