Angular and unrestricted limits of one-parameter semigroups in the unit disk

Abstract

We study local boundary behaviour of one-parameter semigroups of holomorphic functions in the unit disk. Earlier, under some additional condition (the position of the Denjoy-Wolff point) it was shown in [13] that elements of one-parameter semigroups have angular limits everywhere on the unit circle and unrestricted limits at all boundary fixed points. We prove stronger versions of these statements with no assumption on the position of the Denjoy-Wolff point. In contrast to many other problems, in the question of existence for unrestricted limits it appears to be more complicated to deal with the boundary Denjoy-Wolff point (the case not covered in [13]) than with all the other boundary fixed points of the semigroup. © 2014 Elsevier Inc.