Questions about extreme points

We discuss the geometry of the unit ball —specifically, the structure of its extreme points (if any)— in subspaces of $L^{1}$ and $L^{\infty}$ on the circle that are formed by functions with prescribed spectral gaps. A similar issue is considered for kernels of Toeplitz operators in $H^{\infty}$....

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Detalhes bibliográficos
Autor: Dyakonov, Konstantin M.
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2023
País:España
Recursos:Universidad de Barcelona
Repositório:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/217653
Acesso em linha:https://hdl.handle.net/2445/217653
Access Level:Acceso aberto
Palavra-chave:Anàlisi harmònica
Funcions analítiques
Funcions de variables complexes
Espais de Hardy
Harmonic analysis
Analytic functions
Functions of complex variables
Hardy spaces
Descrição
Resumo:We discuss the geometry of the unit ball —specifically, the structure of its extreme points (if any)— in subspaces of $L^{1}$ and $L^{\infty}$ on the circle that are formed by functions with prescribed spectral gaps. A similar issue is considered for kernels of Toeplitz operators in $H^{\infty}$.