The Boundary Value Problem for Relativistic Schrodinger Equation

Infinite order differential operators with small parameter are investigated for solv-ing the relativistic Schroedinger difference equation (singular perturbed differential equation of infinite order) with the quasipotential. It is studying the boundary value problems on the interval [0 ; r ₀], the boundary value problem with periodic and an-tiperiodic boundary conditions on the interval [0 ; r ₀] and the boundary value problem on the positive half-line [0 ; + 1 ) for finding the eigenfunctions and eigenvalues.