TRIGONOMETRIC CHAOS AND Xp 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-Mármol, A.I., Conde-Alonso, J.M., Parcet, J.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2024
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:dnet:digitalcsic_::39cd788f976408b1f7eb8c303b953329
Acceso en línea:http://hdl.handle.net/10261/381577
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85202472590&doi=10.2140%2fapde.2024.17.2561&partnerID=40&md5=d741258728287fdc24deea1687977ca1
Access Level:acceso abierto
Palabra clave:Discrete groups
geometry of L<sub>p</sub> spaces
X<sub>p</sub> inequalities
Hypercube
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. © 2024 MSP (Mathematical Sciences Publishers). Distributed under the Creative Commons Attribution License 4.0 (CC BY). Open Access made possible by subscribing institutions via Subscribe to Open