3 papers
math.ST2019
Copulas and Preserver Problems
Ahmed Sani, loubna Karbil
Preserver problems concern the characterization of operators on general spaces that leave invariant some categories of subsets or ratios. The most known in the mathematical literat…
math.PR2019
Functional treatment of asymmetric copulas
Ahmed Sani, Loubna Karbil
The concept of asymmetric copulas is revisited and is made more precise. We give a rigorous topological argument for opportunity to define asymmetry measures defined recently by K.…
math.FA2019
Boundary values of holomorphic semigroups and fractional integration
Omar EL-Mennaoui, Valentin Keyantuo, Ahmed Sani
The concept of boundary values of holomorphic semigroups in a general Banach space is studied. As an application, we consider the Riemann-Liouville semigroup of integration operato…