Nonperturbative model of hot SU(2) gluodynamics

A hot-gluodynamics model based on taking consistently into account nonperturbative fluctuations of the gluon field in the temperature-deconfining phase is proposed. In order to perform averaging over nonperturbative fields, the gluon system (partition function) is broken down into a fast and a slow subsystem. In one of these subsystems, nonperturbative fields play the role of rapidly changing (stochastic) degrees of freedom, whose effect on soft gluons is considered within the cluster-expansion method for Green’s functions in the nonperturbative background field. The effect of long-wavelength chromomagnetic fluctuations on hard gluons is studied within adiabatic perturbation theory in the strong-field approximation. The pressure and the energy density of SU(2) gluon matter are calculated for T > T _c .