Nonlocal hydrodynamics in the quantum field modelϕ ⁴

Abstract

The procedure of passing from quantum statistical mechanics to the hydrodynamics previously developed by the author is now applied to the quantum field model ϕ⁴. For a certain class of external forces, the equations of many-body systems in quantum theory appear to be equivalent to the equations of nonlocal hydrodynamics. The hydrodynamic nonlocalities arising in constituent relations are expressed through the Green's functions for currents. Some properties of the nonlocal kernels, in particular, the conditions related to dissipation and T-invariance of the model ϕ⁴ (an analogue of Onsager's relations), are deduced from the general symmetry properties. In hydrodynamics, nonlocality allows causality and dissipativity to be consistently combined. The connection between the classical transport coefficients and the hydrodynamic kernels is established. An algorithm for calculating constituent relations by perturbation theory, using the technique of temperature Green's functions, is described.