Let T be an operator of weak types (a, b) and ( p, q), where a< p and b<q. The Marcinkiewicz interpolation theorem and its generalizations due to Boyd, Krein Semenov and others show that T maps certain rearrangement invariant spaces E which are ``not too close'' to L a or L p into certain spaces F.
Interpolation by Weak Chebyshev Spaces
β Scribed by Oleg Davydov; Manfred Sommer
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 214 KB
- Volume
- 102
- Category
- Article
- ISSN
- 0021-9045
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β¦ Synopsis
We present two characterizations of Lagrange interpolation sets for weak Chebyshev spaces. The first of them is valid for an arbitrary weak Chebyshev space U and is based on an analysis of the structure of zero sets of functions in U extending Stockenberg's theorem. The second one holds for all weak Chebyshev spaces that possess a locally linearly independent basis.
2000 Academic Press
1. Introduction
Let U denote a finite-dimensional subspace of real valued functions defined on a totally ordered set K, for example, an arbitrary subset of R.
A finite subset T=[t 1 , ..., t n ] of K, where n=dim U, is called an interpolation set (I-set) w.r.t. U if for any given data [ y 1 , ..., y n ] there exists a unique function u # U such that u(t i )= y i , i=1, ..., n.
π SIMILAR VOLUMES
We prove, by elementary measure theoretic arguments, imbedding theorems for the Lipschitz spaces generated by the weak-L p metric. Our results hold for every p in the range 0< p< and in some cases extend the results known for the L p metric. We also show that our techniques also extend to more gener