On Banach Spaces with the Gelfand-Philips Property.
A Solution to a Problem of de Wilde and Tsirulnikov.
Nonseparability of the quotient space cabv(∑,m;X)/L¹(m;X) for Banach spaces X without the Radon-Nikodym property
It is shown that if (S,∑,m) is an atomless finite measure space and X is a Banach space without the Radon-Nikodym property, then the quotient space cabv(∑,m;X)/L¹(m;X) is nonseparable.
On symmetric bases in nonseparable Banach spaces
On uncountable unconditional bases in Banach spaces
Barrelled spaces with Boolean rings of projections.
The talk presented a survey of results most of which have been obtained over the last several years in collaboration with M.Florencio and P.J.Paúl (Seville). The results concern the question of barrelledness of locally convex spaces equipped with suitable Boolean algebras or rings of projections. They are particularly applicable to various spaces of measurable vector valued functions. Some of the results are provided with proofs that are much simpler than the original ones.
Primariness of some spaces of continuous functions.
Lacunary convergence of series in L revisited.
A simpler proof is given for the recent result of I. Labuda and the author that a series in the space L (lambda) is subseries convergent if each of its lacunary subseries converges.
Arrangements of series preserving their convergence or boundedness
For a map of into itself, consider the induced transformation of series in a topological vector space. Then such properties of this transformation as sending convergent series to convergent series, or convergent series to bounded series, or bounded series to bounded series (and a few more) are mutually equivalent. Moreover, they are equivalent to an intrinsic property of ρ which reduces to those found by Agnew and Pleasants (in the case of permutations) and Wituła (in the general case) as...
On Banach spaces of regulated functions
For a relatively compact subset of the real line , let denote the Banach space (under the sup norm) of all regulated scalar functions defined on . The purpose of this paper is to study those closed subspaces of that consist of functions that are left-continuous, right-continuous, continuous, and have a (two-sided) limit at each point of some specified disjoint subsets of . In particular, some of these spaces are represented as spaces for suitable, explicitly constructed, compact spaces...
True preimages of compact or separable sets for functional analysts
We discuss various results on the existence of ‘true’ preimages under continuous open maps between -spaces, -lattices and some other spaces. The aim of the paper is to provide accessible proofs of this sort of results for functional-analysts.
Maps preserving convergence of series
On vector measures which have everywhere infinite variation or noncompact range
CONTENTS1. Introduction..........................................................................................52. Vector measures with λ-everywhere infinite variation represented by series of simple measures.............113. Semicontinuity of some maps related to the variation map..................................................184. Sets of λ-continuous measures with (λ-) everywhere infinite variation.....................................235. Borel complexity of some spaces of vector measures........................................................266....
Vector series whose lacunary subseries converge
The area of research of this paper goes back to a 1930 result of H. Auerbach showing that a scalar series is (absolutely) convergent if all its zero-density subseries converge. A series in a topological vector space X is called ℒ-convergent if each of its lacunary subseries (i.e. those with ) converges. The space X is said to have the Lacunary Convergence Property, or LCP, if every ℒ-convergent series in X is convergent; in fact, it is then subseries convergent. The Zero-Density Convergence...
Uncomplementability of the spaces of norm continuous functions in some spaces of "weakly" continuous functions
Generalized Helly spaces, continuity of monotone functions, and metrizing maps
Given an ordered metric space (in particular, a Banach lattice) E, the generalized Helly space H(E) is the set of all increasing functions from the interval [0,1] to E considered with the topology of pointwise convergence, and E is said to have property (λ) if each of these functions has only countably many points of discontinuity. The main objective of the paper is to study those ordered metric spaces C(K,E), where K is a compact space, that have property (λ). In doing so, the guiding idea comes...
On the modulus of measures with values in topological Riesz spaces.
The paper is devoted to a study of some aspects of the theory of (topological) Riesz space valued measures. The main topics considered are the following. First, the problem of existence (and, particularly, the so-called proper existence) of the modulus of an order bounded measure, and its relation to a similar problem for the induced integral operator. Second, the question of how properties of such a measure like countable additivity, exhaustivity or so-called absolute exhaustivity, or the properties...
The Nikodym property for ideals of sets defined by matrix summability methods.
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