Spectral asymptotics of Gasymov-Kostyuchenko problems with ''nonsmooth'' coefficients (Q1819294)

The problem of spectral asymptotics of a differential operator defined on an unbounded domain, but with bounded free coefficient, first introduced by A. G. Kostyuchenko, 1967, then in the case of ordinary differential operators solved by M. G. Gasymov, is studied. The smoothness assumptions on the coefficients are significantly weakened. Namely the differentiability of the coefficients is not required. For the operator defined by means of a bilinear form, a theorem on the asymptotic distribution of eigenvalues is proved.