On formation of equation of state of evolving quantum field
  Stylized model of evolution of matter created in ultra relativistic heavy ion collisions is considered. Systematic procedure of computing quantum corrections in the framework of Keldysh formalism is formulated. Analytical expressions for formation of equations of state taking into account leading quantum corrections is worked out, complete description of subleasing corrections and analytical expressions for some of them is presented. 
A.V. Leonidov, A.A. Radovskaya
nucl-th