Function spaces and operator theory form a rich and interconnected subdiscipline of modern analysis, embracing a variety of spaces that measure function regularity and oscillatory behaviour alongside ...

Analytic functions, defined by the property of being locally expressible as convergent power series, form a cornerstone of complex analysis. Differential operators, which act on these functions by ...

We introduce the cosine-type approximation processes in abstract Banach space setting. The historical roots of these processes go back to W. W. Rogosinski in 1926. The given new definitions use a ...