Kinetic properties of pion gas

Kinetic equations for some models of the interacting neutral pion gas are derived in the framework of D. N. Zubarev's nonequilibrium statistical operator method. By means of solving the equations in the approximation of relaxation time the transport coefficients are found and investigated for the relativistic temperature. It is shown that the wellknown result by Iso, Mori, Namiki for the viscosity ν approximately T3 corresponds to the model gphi4. It is found that the transport coefficients increase with the temperature for renormalizable models and decrease for nonrenormalizable ones