Über die Zulässigkeit des Verfahrens von Galerkin bei linearen,nichtselbstadjungierten Eigenwertproblemen

Summary In this report it is proved that the method ofGalerkin remains valid for a certain class of linear, non-self-adjoint eigenvalue problems. This class contains all eigenvalue problems which arise from originally self-adjoint problems by addition of a linear differential expression which destroys the former self-adjointness.Helge von Koch's theory of infinite determinants is used in deriving the above result.