Approximate solutions of equations defined by complex spherical multiplier operators.
Approximately Invariant Subspaces for Unbounded Linear Operators. II.
Approximating curve and strong convergence of the algorithm for the split feasibility problem.
Approximating the fixed points of some nonlinear operator equations
Approximation and asymptotics of eigenvalues of unbounded self-adjoint Jacobi matrices acting in l 2 by the use of finite submatrices
We consider the problem of approximation of eigenvalues of a self-adjoint operator J defined by a Jacobi matrix in the Hilbert space l 2(ℕ) by eigenvalues of principal finite submatrices of an infinite Jacobi matrix that defines this operator. We assume the operator J is bounded from below with compact resolvent. In our research we estimate the asymptotics (with n → ∞) of the joint error of approximation for the eigenvalues, numbered from 1 to N; of J by the eigenvalues of the finite submatrix J...
Approximation and convex decomposition by extremals in a C*-algebra.
Approximation of eigenvalues for unbounded Jacobi matrices using finite submatrices
We consider an infinite Jacobi matrix with off-diagonal entries dominated by the diagonal entries going to infinity. The corresponding self-adjoint operator J has discrete spectrum and our purpose is to present results on the approximation of eigenvalues of J by eigenvalues of its finite submatrices.
Approximation semi-classique de la phase de diffusion pour un potentiel (d'après un travail de D. Robert et H. Tamura)
Approximation spectral d'un opérateur borné et normal à l'aide de ses fonctions de la densité spectrale
Approximation the Shift with Toeplitz Operators.
Approximationseigenschaft, Lifting und Kohomologie bei lokalkonvexen Produktgarben.
Arcangeli's type discrepancy principles for a class of regularization methods using a modified projection scheme.
Arithmetic-geometric-harmonic mean of three positive operators.
Around the Furuta inequality – the operator inequalities .
Arrival time observables in quantum mechanics
Ascent and descent for sets of operators
We extend the notion of ascent and descent for an operator acting on a vector space to sets of operators. If the ascent and descent of a set are both finite then they must be equal and give rise to a canonical decomposition of the space. Algebras of operators, unions of sets and closures of sets are treated. As an application we construct a Browder joint spectrum for commuting tuples of bounded operators which is compact-valued and has the projection property.
Ascent, descent and roots of Fredholm operators
Let T be a Fredholm operator on a Banach space. Say T is rootless if there is no bounded linear operator S and no positive integer m ≥ 2 such that . Criteria and examples of rootlessness are given. This leads to a study of ascent and descent whether finite or infinite for T with examples having infinite ascent and descent.
Ascent spectrum and essential ascent spectrum
We study the essential ascent and the related essential ascent spectrum of an operator on a Banach space. We show that a Banach space X has finite dimension if and only if the essential ascent of every operator on X is finite. We also focus on the stability of the essential ascent spectrum under perturbations, and we prove that an operator F on X has some finite rank power if and only if for every operator T commuting with F. The quasi-nilpotent part, the analytic core and the single-valued extension...
Asymptotic behaviour in the set of nonhomogeneous chains of stochastic operators
We study different types of asymptotic behaviour in the set of (infinite dimensional) nonhomogeneous chains of stochastic operators acting on L¹(μ) spaces. In order to examine its structure we consider different norm and strong operator topologies. To describe the nature of the set of nonhomogeneous chains of Markov operators with a particular limit behaviour we use the category theorem of Baire. We show that the geometric structure of the set of those stochastic operators which have asymptotically...
Asymptotic behaviour of semigroups of operators