Abstract:
The contribution made by interactions of the hydrodynamic modes to the transport
coefficients of a Bose superfluid is investigated. It is shown that the generalized
transport coefficients, which depend on the wave vector and the frequency, can be
expressed exactly in terms of the elements of the mass operator for the matrix
correlation function of the basic hydrodynamic variables. The mode-coupling
approximation in the mass operator is used to obtain a system of integral equations
for the transport coefficients. Explicit expressions for the fluctuation corrections
are obtained in the three-dimensional case. The dispersion of second sound in the
neighborhood of the $\lambda$ point is discussed.