Generalization of the Bogolyubov-Zubarev theorem for dynamic pressure to the case of compressibility

Summary (translated from the Russian): "We present the motivation, formulation and modified proof of the Bogolyubov-Zubarev theorem connecting the pressure of a dynamic object to its energy within the framework of a classical description, and we also obtain a generalization of this theorem to the case of taking account of dynamic compressibility. In both cases the volume of the object is introduced into consideration by means of a singular addition to the Hamiltonian function of the physical object, which allows the explicit use of the notion of Bogolyubov quasiaverages already on the dynamical level of description. We also discuss the connection to an analogous result known as the Helmann-Feynman theorem within the framework of the quantum description of a physical object."