The relativistic KMS condition for the thermal n-point functions of the   P(\phi)_2 model
  Thermal quantum field theories are expected to obey a relativistic KMS condition, which replaces both the relativistic spectrum condition of Wightman quantum field theory and the KMS condition, which characterises equilibrium states in quantum statistical mechanics. In a previous work it has been shown that the two-point function of the thermal $P(\phi)_2$ model satisfies the relativistic KMS condition. Here we extend this result to general $n$-point functions. 
Christian D. J\"akel and Florian Robl
math-ph cond-mat.stat-mech hep-th math.MP