Dependence of the buckling load of a nonshallow arch with respect to the shape of its midcurve
Entropy of -valued operators and diverse applications.
Error-estimates for the method of least squares of finding eigenvalues and eigenfunctions
Espaces de Krein et index des systèmes hamiltoniens
Explicit representation of compact linear operators in Banach spaces via polar sets
We consider a compact linear map T acting between Banach spaces both of which are uniformly convex and uniformly smooth; it is supposed that T has trivial kernel and range dense in the target space. It is shown that if the Gelfand numbers of T decay sufficiently quickly, then the action of T is given by a series with calculable coefficients. This provides a Banach space version of the well-known Hilbert space result of E. Schmidt.
General results on the eigenvalues of operators with gaps, arising from both ends of the gaps. Application to Dirac operators
This paper is concerned with an extension and reinterpretation of previous results on the variational characterization of eigenvalues in gaps of the essential spectrum of self-adjoint operators. We state two general abstract results on the existence of eigenvalues in the gap and a continuation principle. Then these results are applied to Dirac operators in order to characterize simultaneously eigenvalues corresponding to electronic and positronic bound states.
Global Properties of the Minimal Branch of a Class of Nonlinear Variational Problems.
Including eigenvalues of the plane Orr-Sommerfeld problem
In an earlier paper [5] a method for eigenvalue inclussion using a Gerschgorin type theory originating from Donnelly [2] was applied to the plane Orr-Sommerfeld problem in the case of a pure Poiseuile flow. In this paper the same method will be used to deal Poiseuile and Couette flow. Potter [6] has treated this case before with an approximative method.
Iterative solution of eigenvalue problems for normal operators
We will discuss Kellogg's iterations in eigenvalue problems for normal operators. A certain generalisation of the convergence theorem is shown.
L'asymptotique des valeurs propres pour l'opérateur de Schrödinger avec un potentiel périodique perturbé
Limit points of eigenvalues of truncated unbounded tridiagonal operators
Let T be a self-adjoint tridiagonal operator in a Hilbert space H with the orthonormal basis {e n}n=1∞, σ(T) be the spectrum of T and Λ(T) be the set of all the limit points of eigenvalues of the truncated operator T N. We give sufficient conditions such that the spectrum of T is discrete and σ(T) = Λ(T) and we connect this problem with an old problem in analysis.
Monomiality principle and eigenfunctions of differential operators.
Multiplicités des valeurs propres et transformations étoile-triangle des graphes
New characterizations and applications of inhomogeneous Besov and Triebel-Lizorkin spaces on homogeneous type spaces and fractals [Book]
Observability properties of a semi-discrete 1d wave equation derived from a mixed finite element method on nonuniform meshes
The goal of this article is to analyze the observability properties for a space semi-discrete approximation scheme derived from a mixed finite element method of the 1d wave equation on nonuniform meshes. More precisely, we prove that observability properties hold uniformly with respect to the mesh-size under some assumptions, which, roughly, measures the lack of uniformity of the meshes, thus extending the work [Castro and Micu, Numer. Math.102 (2006) 413–462] to nonuniform meshes. Our results...
On a certain algorithm of eigenvalue localization for normal operators
On general Lipschitzian kernels.
On Hardy's inequality and eigenvalue distributions
On peripheral eigenvalues and eigenvectors of certain regular operators. (Über periphere Eigenwerte und Eigenvektoren bei gewissen regulären Operatoren.)
On positive eigenvectors of a linear eigenvalue problem