Low Temperature Physics: 34, 320 (2008); https://doi.org/10.1063/1.2911642 (9 pages)
Infrared peculiarities in the field theory of superfluidity and temperature corrections to the first and second sounds velocities in helium II
Institute of Physics National Academy of Sciences of Ukraine, 46 Nauki Ave., Kiev 03028, Ukraine
S.I. Vilchinskyy, and A.V. Chumachenko
Faculty of Physics, Kiev State University, Acad. Glushkov Pr., 6, Kiev 03022, Ukraine
Received December 6, 2007
Using the modified Popov perturbation theory for strongly correlated Bose systems, which is free from infrared divergencies, high-order perturbative corrections to the self-energy parts of the theory of superfluidity are obtained. The calculation of these high-order corrections reduces to the solution of the kinetic equations from whence the temperature corrections to the velocities of the first and second sounds in the superfluid Bose liquid 4He are calculated. The temperature dependence of the superfluid component density is found using the theoretical model of superfluidity in which the superfluid component is considered as a mixture of the interaction depleted-single-particle and intensive pair condensates.
PACS: 67.25.D– Superfluid phase 4He;
Key words: infrared divergencies, temperature corrections to sound velocities, temperature dependence of superfluid component density.