Functional models up to similarity and a-contractions

Abadias, L. (Universidad de Zaragoza) ; Bello, G. ; Yakubovich, D.

Resumen: We study the generalization of m-isometries and m-contractions (for positive integers m) to what we call a-isometries and a-contractions for positive real numbers a. We show that an operator satisfying a certain inequality in hereditary form is similar to a-contraction. This improvement of [9, Theorem I] is based on some Banach algebras techniques. We show that our operator classes are closely connected with fractional finite differences. Using this techniques, we get that, given 0 < b< a, an a-contraction need not to be a b-contraction in general, but is a b-contraction if a natural additional requirement is imposed.

Idioma: Inglés

DOI: 10.1007/s43037-020-00114-6

Año: 2021

Publicado en: Banach Journal of Mathematical Analysis 15, 2 (2021), 34 [29 pp]
ISSN: 2662-2033

Factor impacto JCR: 1.197 (2021)

Categ. JCR: MATHEMATICS rank: 114 / 333 = 0.342 (2021) - Q2 - T2
Categ. JCR: MATHEMATICS, APPLIED rank: 166 / 267 = 0.622 (2021) - Q3 - T2

Factor impacto CITESCORE: 1.6 - Mathematics (Q3)

Factor impacto SCIMAGO: 0.554 - Analysis (Q2) - Algebra and Number Theory (Q2)

Financiación: info:eu-repo/grantAgreement/ES/DGA-FEDER/E26-17R
Financiación: info:eu-repo/grantAgreement/ES/MINECO-MCIU/PID2019-105979GB-I00

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Análisis Matemático (Dpto. Matemáticas)