Simultaneous approximation of the Feller operator
In this paper, a quantitative estimate for the simultaneous approximation of a function and its derivatives by the Feller operator is established via a probabilistic approach. This covers the cases of some classical approximation operators such as the Bernstein, Szász, Baskakov, and Gamma operators.
Computers and Mathematics with Applications
Anastassiou, G., & Zhou, M. (1996). Simultaneous approximation of the Feller operator. Computers and Mathematics with Applications, 31 (10), 31-44. https://doi.org/10.1016/0898-1221(96)00050-8