Hölder and locally Hölder Continuous Functions, and Open Sets of Class C^k, C^{k,lambda}

Renato Fiorenza has been a professor in mathematical analysis at the University of Naples (Italy) "Federico II" since 1967. He became a professor when Italy was leading the field with Miranda, Caccioppoli, De Giorgi (who solved Hilbert's 19th problem, proving that for a class of elliptic partial differential equations with analytic coefficients the solutions had first derivatives which are Hölder continuous). Renato Fiorenza was an assistant of Caccioppoli. In his career he has established some important results about oblique derivative problems for partial differential equations.

Hölder and locally Hölder continuous functions.- Coordinate changes in Rn. Rotations. Cones in Rn.- Open sets with boundary of class Ck and of classCk. The cone property.- Open sets of class Ck and of class Ck.- Majorization formulas for functions.