The spectrum of the Ekman boundary layer problem
Originating in fluid dynamics, the study of linear stability of an Ekman boundary layer gives rise to a spectral problem for a non-selfadjoint operator matrix family. We present new eigenvalue enclosures for the point spectrum of this family and thereby solve an open problem on the existence of open sets of eigenvalues in domains of Fredholmness posed by L. Greenberg and M. Marletta in 2004. As a consequence, the spectral exactness of domain truncation approximations is valid for arbitrary Reynolds numbers. The talk is based on a joint work with B. Gerhat and O. Ibrogimov.