Analysis of the discrete spectrum of the family of $3\times 3$ operator matrices

Mukhiddin I. Muminov, Tulkin H. Rasulov, Nargiza A. Tosheva

We consider the family of $3\times 3$ operator matrices $\mathbf{H}(K),$ $K\in {\mathbb{T}}^3:=(-\pi ;\pi {]}^3$ associated with the lattice systems describing two identical bosons and one par…