Compact operators and approximation spaces
We investigate compact operators between approximation spaces, paying special attention to the limit case. Applications are given to embeddings between Besov spaces.
Closed operator ideals and limiting real interpolation
We establish interpolation properties under limiting real methods for a class of closed ideals including weakly compact operators, Banach-Saks operators, Rosenthal operators and Asplund operators. We show that they behave much better than compact operators.
Interpolation of the measure of non-compactness by the real method
We investigate the behaviour of the measure of non-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.
Compact operators between K- and J-spaces
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.
Remarks on compact operators between interpolation spaces associated to polygons.
This note deals with interpolation methods defined by means of polygons. We show necessary and sufficient conditions for compactness of operators acting from a J-space into a K-space.
On interpolation of bilinear operators by methods associated to polygons
Stabiliamo teoremi di interpolazione bilineare per una combinazione dei metodi di - e -interpolazione associati ai poligoni, e per il -metodo. Mostriamo che un simile risultato fallisce per il -metodo, e diamo applicazioni all'interpolazione di spazi di operatori.
Inclusion Indices of Quasi-Banach Spaces
We investigate inclusion indices for quasi-Banach spaces. First we consider the case of function spaces on , then the sequence case and finally we develop an abstract approach dealing with indices defined by the real interpolation scale gen- erated by a quasi-Banach couple.
Quantitative estimates for interpolated operators by multidimensional methods.
We describe the behavior of ideal variations under interpolation methods associated to polygons.
Corrigendum on the paper .
Here are given the figures of this paper, initially published with some omissions.
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