Person:
Cobos Díaz, Fernando

First Name

Fernando

Last Name

Cobos Díaz

URI

https://hdl.handle.net/20.500.14352/75635

Affiliation

Universidad Complutense de Madrid

Faculty / Institute

Ciencias Matemáticas

Department

Análisis Matemático Matemática Aplicada

Area

Análisis Matemático

Identifiers

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Now showing 1 - 10 of 17

Compactness interpolation results for bilinear operators of convolution type and for operators of product type
(Journal of Approximation Theory, 2022) Cobos Díaz, Fernando; Fernández-Cabrera Marín, Luz María; Martínez, Antón
We establish compactness interpolation results for bilinear operators of convolution type and for operators of product type among quasi-Banach spaces. We do not assume any auxiliary condition on the spaces.
Compact operators between K - and J -spaces
(Studia Mathematica, 2005) Cobos Díaz, Fernando; Fernández-Cabrera Marín, Luz María; Martínez, Antón
The paper establishes necessary and sufficient conditions for compactness of operators acting between general K -spaces, general J -spaces and operators acting from a J -space into a K -space. Applications to interpolation of compact operators are also given.
Compact operators and approximation spaces
(Colloquium mathematicum, 2014) Cobos Díaz, Fernando; Domínguez Bonilla, Óscar; Martínez, Antón
We investigate compact operators between approximation spaces, paying special attention to the limit case. Applications are given to embeddings between Besov spaces.
Complex Interpolation, Minimal Methods and Compact Operators
(Mathematische Nachrichten, 2004) Cobos Díaz, Fernando; Fernández-Cabrera Marín, Luz María; Martínez, Antón
We characterize compact operators between complex interpolation spaces and between spaces obtained by using certain minimal methods in the sense of Aronszajn and Gagliardo. Applications to interpolation of compact operators are also given.
Inclusion indices of Quasi-Banach Spaces
(Bollettino della Unione Matematica Italiana. Sezione B: articoli di Bollettino dell unione matematica italiana. Sezione B: articoli di ricerca matematica, 2007) Cobos Díaz, Fernando; Fernández-Cabrera Marín, Luz María; Manzano Rodríguez, Antonio; Martínez, Antón
Abstract K and J Spaces and Measure of Non-Compactness
(Mathematische Nachrichten, 2007) Cobos Díaz, Fernando; Fernández-Cabrera Marín, Luz María; Martínez, Antón
We establish a formula for the measure of non-compactness of an operator interpolated by the general real method generated by a sequence lattice Γ. The formula is given in terms of the norms of the shift operators in Γ.
Interpolation of compact bilinear operators among quasi-Banach spaces and applications
(Mathematische Nachrichten, 2018) Cobos Díaz, Fernando; Fernández-Cabrera Marín, Luz María; Martínez, Antón
We study the interpolation properties of compact bilinear operators by the general real method among quasi- Banach couples. As an application we show that commutators of Calderón-Zygmund bilinear operators S : Lp × Lq -? Lr are compact provided that 1/2 < r < 1, 1 < p, q < 8 and 1/p + 1/q = 1/r.
Interpolation of the measure of non-compactness by the real method
(Studia Mathematica, 1999) Cobos Díaz, Fernando; Fernández-Martínez, Pedro; Martínez, Antón
We investigate the behaviour of the measure of Iron-compactness of an operator under real interpolation. Our results refer to general Banach couples. An application to the essential spectral radius of interpolated operators is also given.
Measure of non-compactness and interpolation methods associated to polygons
(Glasgow Mathematical Journal, 1999) Cobos Díaz, Fernando; Fernández-Martínez, Pedro; Martínez, Antón
We establish an estimate for the measure of non-compactness of an interpolated operator acting from a J-space into a K-space. Our result refers to general Banach N-tuples. We also derive estimates for entropy numbers if some of the N-tuples reduce to a single Banach space.
On interpolation of Banach algebras and factorization of weakly compact homomorphisms
(Bulletin des Sciences Mathematiques, 2006) Cobos Díaz, Fernando; Fernández-Cabrera Marín, Luz María; Martínez, Antón
We show a necessary and sufficient condition on the lattice Γ for the general real method (· , ·)Γ to preserve the Banach-algebra structure. As an application we derive factorization of weakly compact homomorphisms through interpolation properties of weakly compact operators.