2024-04-24T23:12:34Zhttps://docta.ucm.es/rest/oai/requestoai:docta.ucm.es:20.500.14352/588082023-07-14T02:00:18Zcom_20.500.14352_14col_20.500.14352_15
A factorization formula for some entropy ideals
Cobos, Fernando
Resina, Ivam
Soria, Fernando
The paper deals with the entropy ideals generated by the Lorentz- Marcinkiewicz spaces of the type λ ∞ (ϕ) where ϕ is a function parameter. The entropy ideal generated by λ ∞ (ϕ) is the set of all operators between Banach spaces whose sequence of the entropy numbers belongs to λ ∞ (ϕ). The entropy ideals play an important role in the characterization of the degree of compactness of weakly singular integral operators. As a continuation of F. Cobos' investigation of the entropy ideals of the type λ p (ϕ), the authors prove a factorization formula saying that the entropy ideal corresponding to the product of two function parameters is the product of the entropy ideals corresponding to the factors. The proof uses the interpolation with function parameters and as a by-product, the authors obtain informations on the behaviour of the entropy numbers under the interpolation.
2023-06-20T18:52:01Z
2023-06-20T18:52:01Z
2023-06-20T18:52:01Z
1988
journal article
https://hdl.handle.net/20.500.14352/58808
1123-2536
http://siba-ese.unisalento.it/index.php/notemat
eng
86-0964-0
https://creativecommons.org/licenses/by-nc-nd/3.0/es/
open access
Atribución-NoComercial-SinDerivadas 3.0 España
Università del Salento