Some Properties of Hausdorff Measure of Noncompactness on Locally Bounded Topological Vector Spaces
Some Ramsey type theorems for normed and quasinormed spaces
We prove that every bounded, uniformly separated sequence in a normed space contains a “uniformly independent” subsequence (see definition); the constants involved do not depend on the sequence or the space. The finite version of this result is true for all quasinormed spaces. We give a counterexample to the infinite version in for each 0 < p < 1. Some consequences for nonstandard topological vector spaces are derived.
Stability of the Cauchy functional equation in quasi-Banach spaces
Let X be a quasi-Banach space. We prove that there exists K > 0 such that for every function w:ℝ → X satisfying ||w(s+t)-w(s)-w(t)|| ≤ ε(|s|+|t|) for s,t ∈ ℝ, there exists a unique additive function a:ℝ → X such that a(1)=0 and ||w(s)-a(s)-sθ(log₂|s|)|| ≤ Kε|s| for s ∈ ℝ, where θ: ℝ → X is defined by for k ∈ ℤ and extended in a piecewise linear way over the rest of ℝ.
Stability of the method of least squares for finding the eigenvalues of a symmetric operator
Strong reflexivity of Abelian groups
A reflexive topological group is called strongly reflexive if each closed subgroup and each Hausdorff quotient of the group and of its dual group is reflexive. In this paper we establish an adequate concept of strong reflexivity for convergence groups. We prove that complete metrizable nuclear groups and products of countably many locally compact topological groups are BB-strongly reflexive.
Subspaces of for that are admissible as kernels.
Symmetric -normed space for
Tensor products in the category of topological vector spaces are not associative
We show by example that the associative law does not hold for tensor products in the category of general (not necessarily locally convex) topological vector spaces. The same pathology occurs for tensor products of Hausdorff abelian topological groups.
The algebraic dimension of linear metric spaces and Baire properties of their hyperspaces.
Answering a question of Halbeisen we prove (by two different methods) that the algebraic dimension of each infinite-dimensional complete linear metric space X equals the size of X. A topological method gives a bit more: the algebraic dimension of a linear metric space X equals |X| provided the hyperspace K(X) of compact subsets of X is a Baire space. Studying the interplay between Baire properties of a linear metric space X and its hyperspace, we construct a hereditarily Baire linear metric space...
The Banach Envelopes of Besov and Triebel-Lizorkin Spaces and Applications to Partial Differential Equations.
The basic sequence problem
We construct a quasi-Banach space X which contains no basic sequence.
The differences of inclusion map operators between rearrangement invariant spaces on finite and sigma-finite measure spaces.
The Dugundji extension theorem and extension degree
The Hypercyclicity Criterion for sequences of operators
We show that under no hypotheses on the density of the ranges of the mappings involved, an almost-commuting sequence (Tₙ) of operators on an F-space X satisfies the Hypercyclicity Criterion if and only if it has a hereditarily hypercyclic subsequence , and if and only if the sequence (Tₙ ⊕ Tₙ) is hypercyclic on X × X. This strengthens and extends a recent result due to Bès and Peris. We also find a new characterization of the Hypercyclicity Criterion in terms of a condition introduced by Godefroy...
The Mackey completions of some interpolation F-spaces
The Mackey-Arens theorem for non-locally convex spaces.
Let R be a subcategory of the category of all topological vector spaces. Let E be an element of R. The problem of the existence of the finest R-topology on E with the same continuous linear functionals as the original one is discussed. Remarks concerning the Hahn-Banach Extension Property are included.
The Nikodym property for ideals of sets defined by matrix summability methods.
The strongest vector space topology is locally convex on separable linear subspaces
Let X be a real or complex vector space equipped with the strongest vector space topology . Besides the result announced in the title we prove that X is uncountable-dimensional if and only if it is not locally pseudoconvex.
The theory of bounding subsets of topological vector spaces without convexity condition
The three space problem for locally bounded -spaces