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The lattice copies of 1 in Banach lattices

Marek Wójtowicz (2001)

Commentationes Mathematicae Universitatis Carolinae

It is known that a Banach lattice with order continuous norm contains a copy of 1 if and only if it contains a lattice copy of 1 . The purpose of this note is to present a more direct proof of this useful fact, which extends a similar theorem due to R.C. James for Banach spaces with unconditional bases, and complements the c 0 - and -cases considered by Lozanovskii, Mekler and Meyer-Nieberg.

The Levi problem for domains spread over locally convex spaces with a finite dimensional Schauder decomposition

Martin Schottenloher (1976)

Annales de l'institut Fourier

It is proved that the Levi problem for certain locally convex Hausdorff spaces E over C with a finite dimensional Schauder decomposition (for example for Fréchet or Silva spaces with a Schauder basis) the Levi problem has a solution, i.e. every pseudoconvex domain spread over E is a domain of existence of an analytic function. It is also shown that a pseudoconvex domain spread over a Fréchet space or a Silva space with a finite dimensional Schauder decomposition is holomorphically convex and satisfies...

The Lévy laplacian and differential operators of 2-nd order in Hilbert spaces

Roman Lávička (1998)

Commentationes Mathematicae Universitatis Carolinae

We shall show that every differential operator of 2-nd order in a real separable Hilbert space can be decomposed into a regular and an irregular operator. Then we shall characterize irregular operators and differential operators satisfying the maximum principle. Results obtained for the Lévy laplacian in [3] will be generalized for irregular differential operators satisfying the maximum principle.

The Lindelöf property in Banach spaces

B. Cascales, I. Namioka, J. Orihuela (2003)

Studia Mathematica

A topological space (T,τ) is said to be fragmented by a metric d on T if each non-empty subset of T has non-empty relatively open subsets of arbitrarily small d-diameter. The basic theorem of the present paper is the following. Let (M,ϱ) be a metric space with ϱ bounded and let D be an arbitrary index set. Then for a compact subset K of the product space M D the following four conditions are equivalent: (i) K is fragmented by d D , where, for each S ⊂ D, d S ( x , y ) = s u p ϱ ( x ( t ) , y ( t ) ) : t S . (ii) For each countable subset A of D, ( K , d A ) is...

The Lizorkin-Freitag formula for several weighted L p spaces and vector-valued interpolation

Irina Asekritova, Natan Krugljak, Ludmila Nikolova (2005)

Studia Mathematica

A complete description of the real interpolation space L = ( L p ( ω ) , . . . , L p ( ω ) ) θ , q is given. An interesting feature of the result is that the whole measure space (Ω,μ) can be divided into disjoint pieces Ω i (i ∈ I) such that L is an l q sum of the restrictions of L to Ω i , and L on each Ω i is a result of interpolation of just two weighted L p spaces. The proof is based on a generalization of some recent results of the first two authors concerning real interpolation of vector-valued spaces.

The Maurey extension property for Banach spaces with the Gordon-Lewis property and related structures

P. G. Casazza, N. J. Nielsen (2003)

Studia Mathematica

The main result of this paper states that if a Banach space X has the property that every bounded operator from an arbitrary subspace of X into an arbitrary Banach space of cotype 2 extends to a bounded operator on X, then every operator from X to an L₁-space factors through a Hilbert space, or equivalently B ( , X * ) = Π ( , X * ) . If in addition X has the Gaussian average property, then it is of type 2. This implies that the same conclusion holds if X has the Gordon-Lewis property (in particular X could be a Banach...

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