RT Journal Article
T1 A factorization formula for some entropy ideals
A1 Cobos Díaz, Fernando
A1 Resina, Ivam
A1 Soria, Fernando
AB 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.
PB Università del Salento
SN 1123-2536
YR 1988
FD 1988
LK https://hdl.handle.net/20.500.14352/58808
UL https://hdl.handle.net/20.500.14352/58808
LA eng
NO Fundación de Apoyo a la Investigación del Estado de São Paulo (Brasil)
DS Docta Complutense
RD 27 jul 2024