2024-04-13T21:20:19Zhttps://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
00925njm 22002777a 4500
dc
Cobos, Fernando
author
Resina, Ivam
author
Soria, Fernando
author
1988
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.
1123-2536
https://hdl.handle.net/20.500.14352/58808
http://siba-ese.unisalento.it/index.php/notemat
A factorization formula for some entropy ideals