Trigonometric chaos and X p inequalities, I: Balanced Fourier truncations over discrete groups

We investigate L p-estimates for balanced averages of Fourier truncations in group algebras, in terms of “differential operators” acting on them. Our results extend a fundamental inequality of Naor for the hypercube (with profound consequences in metric geometry) to discrete groups. Different inequa...

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Detalles Bibliográficos
Autores: Cano Marmol, Antonio Ismael, Conde Alonso, José Manuel, Parcet Hernández, Javier
Tipo de recurso: artículo
Fecha de publicación:2024
País:España
Institución:Universidad Autónoma de Madrid
Repositorio:Biblos-e Archivo. Repositorio Institucional de la UAM
Idioma:inglés
OAI Identifier:oai:repositorio.uam.es:10486/715657
Acceso en línea:http://hdl.handle.net/10486/715657
https://dx.doi.org/10.2140/apde.2024.17.2561
Access Level:acceso abierto
Palabra clave:Xp inequalities
hypercube
discrete groups
geometry of Lp spaces
Matemáticas
Descripción
Sumario:We investigate L p-estimates for balanced averages of Fourier truncations in group algebras, in terms of “differential operators” acting on them. Our results extend a fundamental inequality of Naor for the hypercube (with profound consequences in metric geometry) to discrete groups. Different inequalities are established in terms of “directional derivatives” which are constructed via affine representations determined by the Fourier truncations. Our proofs rely on the Banach Xp nature of noncommutative L p-spaces and dimension-free estimates for noncommutative Riesz transforms. In the particular case of free groups we use an alternative approach based on free Hilbert transforms