TWO-TERM ASYMPTOTICS OF SOLUTIONS OF SPECTRAL PROBLEMS WITH SINGULAR PERTURBATIONS
С. А. Назаров · Mathematics of the USSR-Sbornik · 1991
Two groups of singularly perturbed boundary value problems for eigenvalues are considered. The first group contains the following types of perturbations: a small parameter in front of the leading derivatives in the equation or in the boundary condition, a domain with rapidly oscillating boundary, or a thin domain. Problems with perturbations of the data on a set with small diameter e constitute the second group.