5 papers
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…
Simultaneous approximation by operators of exponential type
Ulrich Abel
There are many results on the simultaneous approximation by sequences of special positive linear operators. In the year 1978, Ismail and May as well as Volkov independently studied…
A problem of I. Raşa on Bernstein polynomials and convex functions
Ulrich Abel
We present an elementary proof of a conjecture by I. Raşa which is an inequality involving Bernstein basis polynomials and convex functions. It was affirmed in positive very recent…
Complete Monotonicity and Zeros of Sums of Squared Baskakov Functions
Ulrich Abel, Wolfgang Gawronski, Thorsten Neuschel
We prove complete monotonicity of sums of squares of generalized Baskakov basis functions by deriving the corresponding results for hypergeometric functions. Moreover, in the centr…