On some properties of general linear operators
Per‐Olov Löwdin · International Journal of Quantum Chemistry · 1993
Abstract Some elementary properties of a general linear operator, which is defined on a Hilbert space but is not necessarily self‐adjoint, are briefly reviewed: the classical canonical form, the bi‐orthogonality theorem, the bivariational principle, the spectral resolution of the resolvent, and the properties of exponential forms. © 1993 John Wiley & Sons, Inc.