6 papers
Complete asymptotic expansion for a Durrmeyer variant of operators based on Hermite polynomials
Ulrich Abel, Naim L. Braha
In this paper, we study a Durrmeyer variant of the positive linear operators based on two-variable Hermite polynomials recently introduced by G. Krech (2016). Our main objective is…
Korovkin type theorems for operators acting on functions of polynomial and exponential growth on
Ulrich Abel, Ana-Maria Acu, Margareta Heilmann +1
We prove two Korovkin-type approximation theorems for sequences of positive linear operators acting on continuous functions on . Under the assumption of pointwise conve…
A representation for the integral kernel of the composition of multivariate Bernstein-Durrmeyer operators
Ulrich Abel, Ana Maria Acu, Margareta Heilmann +1
This paper presents a representation for the kernel of the composition of multivariate Bernstein-Durrmeyer operators for functions defined on the standard simplex in …
Kernels for composition of positive linear operators
Ulrich Abel, Ana Maria Acu, Margareta Heilmann +1
This paper investigates the composition of Bernstein--Durrmeyer operators and Szász--Mirakjan--Durrmeyer operators, focusing on the structure and properties of the associated kerne…
Commutativity and spectral properties for a general class of Szasz-Mirakjan-Durrmeyer operators
Ulrich Abel, Ana Maria Acu, Margareta Heilmann +1
In this paper we present commutativity results for a general class of Szasz-Mirakjan-Durrmeyer type operators and associated differential operators and investigate their eigenfunct…
Asymptotic properties for a general class of Szasz-Mirakjan-Durrmeyer operators
Ulrich Abel, Ana Maria Acu, Margareta Heilmann +1
In this paper we introduce a general family of Szász--Mirakjan--Durrmeyer type operators depending on an integer parameter . They can be viewed as a generalizatio…