High-temperature behavior of the partition function for the $P(\varphi)_2$ model of Euclidean field theory

The $P(\varphi)_2$ model of Euclidean (quantum) field theory on a bounded interval with zero-value boundary conditions is considered. An asymptotic representation of the partition function is obtained in the form of a product of the partition function of the free field and a factor that depends on the interaction. Some physical consequences of the result are discussed.