Korovkin sets and mean ergodic theorems.
Korovkin Theorems for Adapted Spaces with Respect to a Positive Operator.
Korovkin-type convergence results for non-positive operators
Korovkin-type approximation theory usually deals with convergence analysis for sequences of positive operators. In this work we present qualitative Korovkin-type convergence results for a class of sequences of non-positive operators, more precisely regular operators with vanishing negative parts under a limiting process. Sequences of that type are called sequences of almost positive linear operators and have not been studied before in the context of Korovkin-type approximation theory. As an example...
-approximation by the method of integral Meyer-König and Zeller operators
-convergence of Bernstein-Kantorovich-type operators
We study a Kantorovich-type modification of the operators introduced in [1] and we characterize their convergence in the -norm. We also furnish a quantitative estimate of the convergence.
Le théorème de Korovkin dans et
Lipschitz-Nikolskii constants and asymptotic simultaneous approximation of the Mn-operators. (Short Communication).
Lipschitz-Nikolskii constants and asymptotic simultaneous approximation of the Mn-operators.
Lipschitz-Nikolskii Constants for the Gamma Operators of Müller.
Lupaş-Durrmeyer operators.
Minimal projections in tensor product spaces.
Minimal projections onto subspaces of l∞(n) of codimension 2.
Minimal projections with respect to various norms
A theorem of Rudin permits us to determine minimal projections not only with respect to the operator norm but with respect to various norms on operator ideals and with respect to numerical radius. We prove a general result about N-minimal projections where N is a convex and lower semicontinuous (with respect to the strong operator topology) function and give specific examples for the cases of norms or seminorms of p-summing, p-integral and p-nuclear operator ideals.
Mixed K-Functionals: A Measure of Smoothness for Blending-type Approximation.
Nachtrag zu G. Leha: Relative Korovkin-Sätze und Ränder.
Numerical integration with weights of convex functions of algebraic polynomials
On a general class of linear and positive operators.
On a problem of A. Lupaş.
On approximation of copulas.
On approximation of functions by generalized Abel--Poisson operators.