A characterization of formally symmetric unbounded operators.
A Convergence Theorem for Selfadjoint Operators Applicable to Dirac Operators with Cutoff Potentials.
A generalization related to Schrödinger operatorswith a singular potential.
A Geometrie Proof of the Spectral Theorem for Unbounded Self-Adjoint Operators.
A minimax principle for eigenvalues in spectral gaps: Dirac operators with Coulomb potentials.
A non elliptic spectral problem related to the analysis of superconducting micro-strip lines
This paper is devoted to the spectral analysis of a non elliptic operator , deriving from the study of superconducting micro-strip lines. Once a sufficient condition for the self-adjointness of operator has been derived, we determine its continuous spectrum. Then, we show that is unbounded from below and that it has a sequence of negative eigenvalues tending to . Using the Min-Max principle, a characterization of its positive eigenvalues is given. Thanks to this characterization, some conditions...
A non elliptic spectral problem related to the analysis of superconducting micro-strip lines
This paper is devoted to the spectral analysis of a non elliptic operator A , deriving from the study of superconducting micro-strip lines. Once a sufficient condition for the self-adjointness of operator A has been derived, we determine its continuous spectrum. Then, we show that A is unbounded from below and that it has a sequence of negative eigenvalues tending to -∞. Using the Min-Max principle, a characterization of its positive eigenvalues is given. Thanks to this characterization, some...
A note on Dirac operators
A structure theorem Lie algebras of unbounded derivations in -algebras
A study of an operator arising in the theory of circular plates
The operator , , , is shown to be essentially self-adjoint, positive definite with a compact resolvent. The conditions on (in fact, on a general symmetric operator) are given so as to justify the application of the Fourier method for solving the problems of the types and , respectively.
A theorem on "localized" self-adjointness of Schrödinger operators with potentials.
A topological characterization of the product of two closed operators
The purpose of this work is to give a topological condition for the usual product of two closed operators acting in a Hilbert space to be closed.
A unitary invariant for pairs of self-adjoint operators.
Absence of the singular continuous component in the spectrum of analytic direct integrals.
Algebraic sum of unbounded normal operators and the square root problem of Kato
Almost commuting self-adjoint matrices - a short proof of Huaxin Lin's theorem.
An abstract approach to some spectral problems of direct sum differential operators.
An approximate method for determination of eigenvalues and eigenvectors of self-adjoint operators
An Example of Quantum Exponential Process.
Approximate determination of eigenvalues and eigenvectors of selfadjoint operators