Procedure of quasi-averaging for heterophase mixtures

For a continuous heterophase system of arbitrary type the procedure of averaging over heterophase fluctuations is defined. The consideration is based on the use of the Gibbs quasi-equilibrium ensembles in the method of separating surfaces. Averaging over phase configurations is given by means of a functional integration over characteristic functions of phase submanifolds. As an illustration, a renormalized Hamiltonian for a system with a two-particle interaction is found. Convenient methods of separating phases and of calculating the corresponding quasi-averages are formulated.