New parameters and Lebesgue-type estimates in greedy approximation

The purpose of this paper is to quantify the size of the Lebesgue constants ()∞ =1 associated with the thresholding greedy algorithm in terms of a new generation of parameters that modulate accurately some features of a general basis. This fine tuning of constants allows us to provide an answer to t...

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Detalles Bibliográficos
Autores: Albiac Alesanco, Fernando José, Ansorena, José L., Berná, Pablo M.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2022
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/45056
Acceso en línea:https://hdl.handle.net/2454/45056
Access Level:acceso abierto
Palabra clave:Lebesgue constants
Greedy approximation
Descripción
Sumario:The purpose of this paper is to quantify the size of the Lebesgue constants ()∞ =1 associated with the thresholding greedy algorithm in terms of a new generation of parameters that modulate accurately some features of a general basis. This fine tuning of constants allows us to provide an answer to the question raised by Temlyakov in 2011 to find a natural sequence of greedy-type parameters for arbitrary bases in Banach (or quasi-Banach) spaces which combined linearly with the sequence of unconditionality parameters ()∞ =1 determines the growth of ()∞ =1. Multiple theoretical applications and computational examples complement our study.