Quasi-relativistic Boltzmann equation for systems with short-distance forces

Systems are referred to as quasirelativistic if terms up to the order of v²/c² suffice to describe them; v is the particle velocity, c is the light velocity. Systems of neutral particles are considered with nonvanishing interaction forces at such short distances that the interaction delay can be ignored. Equations are derived for the correlation functions using the Lagrange function which is known in the quasirelativistic approximation; hence using the N. N. Bogolyubov method the quasirelativistic analog is obtained of the Boltzmann equation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 17, No. 2, pp. 78–82, February, 1974.In conclusion the authors consider it their pleasant duty to express their thanks to N. N. Bogolyubov, B. L. Bonch-Bruevich, and N. A. Chernikov for discussing with them the preprint of this article [9].