Well-Posedness of the Generalized Samarskii–Ionkin Problem for Elliptic Equations in a Cylindrical Domain

We study the well-posedness of some analogs of the nonlocal Samarskii–Ionkin problem for second-order elliptic equations in Sobolev spaces. For the problems in question, existence and uniqueness theorems are proved for regular solutions, i.e., solutions that have all generalized Sobolev derivatives occurring in the corresponding equation. Some spectral problems for elliptic equations with the nonlocal Samarskii–Ionkin condition are studied.