Möller, ManfredZinsou, Bertin2016-10-042016-10-042015-12Möller, M., Zinsou, B. Self-adjoint higher order differential operators with eigenvalue parameter dependent boundary conditions. Bound Value Probl 2015, 79 (2015). https://doi.org/10.1186/s13661-015-0341-51687-2762 (print)1687-2770 (online)http://hdl.handle.net/10539/21124Eigenvalue problems for even order regular quasi-differential equations with boundary conditions which depend linearly on the eigenvalue parameter λ can be represented by an operator polynomial (Formula presented.) where M is a self-adjoint operator. Necessary and sufficient conditions are given such that also K and A are self-adjoint.en© 2015 Möller and Zinsou. This article is distributed under the terms of the Creative Commons Attribution 4.0 International LicenseEigenvalue dependent boundary conditionsHigher order differential operatorQuasi-derivativeSelf-adjoint boundary conditionsOperator polynomialArticle