Asymptotic behaviour of the discrete spectrum of aquasi-periodic boundary value problem for atwo-dimensional hyperbolic equation

摘要

This paper is concerned with the asymptotic properties of the discrete spectrum of two-dimensional self-adjoint operators of hyperbolic type. For the operator of the model quasi-periodic boundary value problem associated with aself-adjoint hyperbolic equation with smooth coefficients on atwo-dimensional torus we obtain an asymptotic formula for the distribution function of the eigenvalues. Bibliography: 9 titles.