A boundary value problem with a discontinuous coefficient and containing a spectral parameter in the boundary condition.
A continuation method on locally convex spaces and applications to ordinary differential equations on noncompact intervals
A Dirichlet Type Result for Ordinary Differential Operators.
A new approach to inverse spectral theory. I: Fundamental formalism.
A new phase space localization technique with application to the sum of negative eigenvalues of Schrödinger operators
A note on eigenvalues of ordinary differential operators.
In this follow-up on the work of Fefferman-Seco [FS] an improved condition for the discrete eigenvalues of the operator -d2 / dx2 + V(x) is established for V(x) satisfying certain hypotheses. The eigenvalue condition in [FS] establishes eigenvalues of this operator to within a small error. Through an obervation due to C. Fefferman, the order of accuracy can be improved if a certain condition is true. This paper improves on the result obtained in [FS] by showing that this condition does indeed hold....
A note on singular and degenerate abstract equations
Si considera l’equazione astratta , dove
A simple proof of the continuity of the higher order Riesz transforms with respect to the gaussian measure
A singular spectral identity and inequality involving the Dirichlet integral of an ordinary differential expression
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 Sturm-Liouville problem with spectral and large parameters in boundary conditions and the associated Cauchy problem
We study a Sturm-Liouville problem containing a spectral parameter in the boundary conditions. We associate to this problem a self-adjoint operator in a Pontryagin space Π₁. Using this operator-theoretic formulation and analytic methods, we study the asymptotic behavior of the eigenvalues under the variation of a large physical parameter in the boundary conditions. The spectral analysis is applied to investigate the well-posedness and stability of the wave equation of a string.
A trace formula of a boundary value problem for the operator Sturm-Liouville equation.
A Useful Banach Algebra.
Absolute Continuity of the Essential Spectrum of - ... + q (t) without Monotony of q.
Abstract singular hyperbolic equations
Si annunziano alcuni risultati di esistenza e unicità per l’equazione astratta singolare nel caso iperbolico.
Adjoint and self-adjoint differential operators on graphs.
Algunas Propiedades De Regularidad De Las Ecuaciones Diferenciales Complejas.
Almost periodic Sturm-Liouville operators with Cantor homogeneous spectrum.
An a posteriori Error Estimation of the Rayleigh-Ritz Eigenvalues.
An abstract version of the resonance theorem