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 ...

The paper deals with the computation of functions of fractional powers of differential operators. The spectral properties of these operators naturally suggest the use of rational approximations. In ...