Sharp constants and extremal functions in inequalities for derivatives
The paper deals with some extremal problem connected with inequalities for derivatives. Both the problem and results are too technical to be reproduced here. Theorems are concerned mainly with the existence of solutions, existence of extremal functions and with their group property. An essential part of the paper consists of comments on earlier results in the field by Kolmogoroff, Hardy, Littlewood and Pólya, Stein, Arestoff, Berdyshev and others.
scientific article; zbMATH DE number 4010828