Sobre la convergencia, casi convergencia y A-sumabilidad de operadores conservativos

Abstract

This doctoral dissertation deals with the approximation of functions by sequences of linear operators. The usual convergence is replaced by almost convergence and matrix summability. Beyond the positivity of the operators involved in the approximation processes , more general shape preserving approximation properties are considered. Quantitative results, as well as results on asymptotic formulae and saturation are obtained. Finally, a parallel study under the more general setting given by statistical summability is proposed.