MOLECULAR HYDRODYNAMICS OF A WEAKLY DEGENERATE NONIDEAL BOSE-GAS .2. GREEN-FUNCTIONS AND KINETIC COEFFICIENTS

The nonideal degenerate Bose-system at a temperature close to zero is investigated by N. N. Bogolyubov and D. N. Zubarev's method of collect ive variables. Applicable to a wide range of frequencies and wave vect ors, interpolated expressions for the Green functions of the densities cf conserved quantities and for the superfluid velocity potential are derived from exact relations. The criteria defining the validity doma in of the hydrodynamic approximation are obtained. The kinetic coeffic ients of two-liquid hydrodynamics at temperatures close to zero are ca lculated for a weakly nonideal Bose-gas. A comparison with the method employing the kinetic equation for quasi-particles is made.