Three-dimensional analog of the Tomonaga model of a system of interacting Fermi particles

A model is proposed for a system of interacting Fermi particles which is a three-dimensional analog of the Tomonaga model. The thermodynamic functions and particle momentum distribution functions are computed. It is shown that, in contrast to the one-dimensional Tomonaga model, the jump in the distribution function on the Fermi surface is conserved in the three-dimensional case. The possibility of describing the properties of He3 in superfluid He4 within the framework of the proposed model is discussed.