Functions in N+ with the positive real parts on the boundary

Nakazi, T.

Hokkaido University Preprint Series in Mathematics, 2000, 486, 1-21

Permalink : https://doi.org/10.14943/83632

このアイテムのアクセス数:737件（2026-08-10 13:35 集計）

ファイル	フォーマット	サイズ	閲覧回数	説明
re486	pdf	859 KB	407

アクセス権	open access
DOI	https://doi.org/10.14943/83632
URI	https://hdl.handle.net/2115/69236
タイトル	Functions in N+ with the positive real parts on the boundary
著者	著者名 Nakazi, T.
言語	英語
キーワード	Hardy space
	exposed point
	extremal problem
	existence of solutions
	Smirnov class
	outer function
	positive real part
発行日	2000-07-01
出版者	Department of Mathematics, Hokkaido University
収録物名	Hokkaido University Preprint Series in Mathematics
巻(号)	486
ページ	1-21
抄録	An essentially bounded function</> on the unit circle gives a continuous linear functional T,p on the Hardy space H1 • p( </>) denotes a set of all complex numbers s such that there exists at least one function which attains the norm of T¢,-s· In a previous paper, we showed that C\p(</>) is empty or an open disc. Unfortunately we did not know when p( </>) is open or closed. In this paper, we study when p( </>) is open or closed. Moreover the functions in the Smirnov class N+ whose real parts are nonnegative on the unit circle are described and studied. Then we give new characterizations of exposed points in the unit ball of H1 and we determine when th􀀕 sum of two inner functions is outer. As an result, we can describe all functions which have their Denjoy-Wolff points on the unit circle.
資源タイプ	紀要論文
出版タイプ	Version of Record