An asymptote of hydrodynamic nonlocality kernels in relativistic gas kinetic theory

It was demonstrated in [1–6] that a description of relativistic and nonrelativistic gases in the context of kinetic theory in the class of hydrodynamic sources is equivalent to a hydrodynamic description. In this case, a hydrodynamic model is nonlocal in space and time and combines consistently the causality and dissipativity principles. In the present work, a problem of calculating hydrodynamic nonlocality kernels in the kinetic theory of a relativistic nondegenerate gas is investigated for the collision integral in a general form. A representation for kernels in the limit of high frequencies and short waves is obtained in the form of an asymptotic series.