Vilchynskyy S. The superfluid hydrodynamics and the excitations types in the quantum bose-liquids in the presence of two condencates.

In dissertation the phenomenological and microscopical methods of de-scribing the dynamic properties of relativistic and nonrelativistic superfluid sy-stems in the presence of two coherent interacting condensates are proposed. Relativistic of thermo-.and hydrodynamics of two-condensate superfluid sys-tem taking into account of the interaction of the condensates with each other and the presence in system of vortex excitations and dissipative phenomena. The analytical studies of the influence of the effect of mutual pulling by super-fluid components on charakter of acoustic excitations in the relyativistic super-fluid system are carried out and the vortex solutions lorentc.covapiant equa-tions are obtained. The systems of equations of the vortex dynamics of soluti-on of two nonrelativistic superfluid liquids are obtained both taking into acco-unt the interaction of the condensates with each other and without it and are carried out the analytical calculations of the ratio of the intensities of waves "first" and "second" the fifth sounds in to such of solution. One introduces a model of the superfluid state of a Bose liquid with repulsion between bosons, in which at T=0, along with a weak single-particle Bose-Einstein condensate, the-re exists an intensive pair coherent condensate, analogous to the Cooper condensate in a Fermi liquid with attraction between fermions. A closed system of nonlinear integral equations for the normal and anomalous self-energy parts is solved numerically, and a quasiparticle spectrum is obtained, which is in good agreement with the experimental spectrum of elementary excitations in superfluid 4He. It is shown that the roton minimum in the spectrum is associated with the negative minimum of the Fourier component of the pair interaction potential. The temperature dependences of the densities of single-particle con-densate and summary density of the superfluid component are obtained.