English
Related papers

Related papers: Fully closed maps and LUR renormability

200 papers

We show that $C(X)$ admits an equivalent pointwise lower semicontinuous locally uniformly rotund norm provided $X$ is Fedorchuk compact of spectral height 3. In other words $X$ admits a fully closed map $f$ onto a metric compact $Y$ such…

Functional Analysis · Mathematics 2018-11-26 S. P. Gul'ko , A. V. Ivanov , M. S. Shulikina , S. Troyanski

We introduce the concept of F-decomposable systems, well-ordered inverse systems of Hausdorff compacta with fully closed bonding mappings. A continuous mapping between Hausdorff compacta is called fully closed if the intersection of the…

Functional Analysis · Mathematics 2025-05-20 Todor Manev

We construct an LUR-norm on the space C(K) which is lower semicontinuous with respect to the pointwise topology for any Fedorchuk compactum of height 3.

Functional Analysis · Mathematics 2018-07-18 S. P. Gul'ko , A. V. Ivanov , S. Troyanski , M. S. Shulikina

Let $X$ be a locally compact topological space, $(Y,d)$ be a boundedly compact metric space and $LB(X,Y)$ be the space of all locally bounded functions from $X$ to $Y$. We characterize compact sets in $LB(X,Y)$ equipped with the topology of…

General Topology · Mathematics 2018-03-29 Ľubica Holá , Dušan Holý

Consider a Hausdorff space (X,T) and a set C of converging nets in X. By virtue of the limit uniqueness, the relation Lim which assigns each member x of X to every net N lying in C that converges to x is a map. Of course, structuring C with…

General Topology · Mathematics 2007-05-23 J. E. Palomar Tarancon

Let $\mathcal{F} $ be a pointwise almost periodic decomposition of a compact metrizable space $X$. Then $\mathcal{F} $ is $R$-closed if and only if $\hat{\mathcal{F}} $ is usc. Moreover, if there is a finite index normal subgroup $H$ of an…

Dynamical Systems · Mathematics 2012-11-07 Tomoo Yokoyama

A topological space is locally equiconnected if there exists a neighborhood $U$ of the diagonal in $X\times X$ and a continuous map $\lambda:U\times[0,1]\to X$ such that $\lambda(x,y,0)=x$, $\lambda(x,y,1)=y$ et $\lambda(x,x,t)=x$ for…

General Topology · Mathematics 2010-10-13 Robert Cauty

We prove that a Banach space of continuous functions $C(K)$ has a renorming that is uniformly rotund in every direction (URED) if and only if the compact space $K$ supports a strictly positive measure

Functional Analysis · Mathematics 2020-05-01 Antonio Avilés , Stanimir Troyanski

In this paper we develop a technique of constructing uni- formly continuous maps between function spaces Cp(X) endowed with the pointwise topology. We prove that if a space X is compact metrizable and strongly countable-dimensional, then…

General Topology · Mathematics 2017-10-31 Rafal Gorak , Mikolaj Krupski , Witold Marciszewski

We consider *-linear maps into a commutative C*-algebra C (X) of continuous functions on a locally compact Hausdorff space X with certain specified properties and prove two results: (1) an extension result for a class of *-linear maps Y -->…

Functional Analysis · Mathematics 2013-07-24 Ulrich Haag

We examine conditions on a (compact metrizable) space $X$ such that for any space $Y$ and closed subspace $Z$, the set of continuous functions from $Z$ to $X$ which extend to $Y$ is either open or closed in the set of continuous functions…

General Topology · Mathematics 2012-07-31 Bruce Blackadar

Let $X$ be a Hausdorff compact space and $C(X)$ be the algebra of all continuous complex-valued functions on $X$, endowed with the supremum norm. We say that $C(X)$ is (approximately) $n$-th root closed if any function from $C(X)$ is…

Functional Analysis · Mathematics 2008-02-28 N. Brodskiy , J. Dydak , A. Karasev , K. Kawamura

A compactness of the Revuz map is established in the sense that the locally uniform convergence of a sequence of positive continuous additive functionals is derived in terms of their smooth measures. To this end, we first introduce a metric…

Probability · Mathematics 2024-05-08 Yasuhito Nishimori , Matsuyo Tomisaki , Kaneharu Tsuchida , Toshihiro Uemura

Fedorchuk's fully closed (continuous) maps and resolutions are applied in constructions of non-metrizable higher-dimensional analogues of Anderson, Choquet, and Cook's continua. Certain theorems on dimension-lowering maps are proved for…

General Topology · Mathematics 2010-10-19 Jerzy Krzempek

Three themes of general topology: quotient spaces; absolute retracts; and inverse limits - are reapproached here in the setting of metrizable uniform spaces, with an eye to applications in geometric and algebraic topology. The results…

Geometric Topology · Mathematics 2022-11-21 Sergey A. Melikhov

We consider two natural topologies on the space $S(X\times Y,Z)$ of all separately continuous functions defined on the product of two topological spaces $X$ and $Y$ and ranged into a topological or metric space $X$. These topologies are the…

General Topology · Mathematics 2025-01-03 Oleksandr Maslyuchenko , Vadym Myronyk , Roman Ivasiuk

A convex subset X of a linear topological space is called compactly convex if there is a continuous compact-valued map $\Phi:X\to exp(X)$ such that $[x,y]\subset\Phi(x)\cup \Phi(y)$ for all $x,y\in X$. We prove that each convex subset of…

Functional Analysis · Mathematics 2012-12-19 T. Banakh , M. Mitrofanov , O. Ravsky

Let $f\colon X\to Y$ be a perfect surjective map of metrizable spaces. It is shown that if $Y$ is a $C$-space (resp., $\dim Y\leq n$ and $\dim f\leq m$), then the function space $C(X,\uin^{\infty})$ (resp., $C(X,\uin^{2n+1+m})$) equipped…

General Topology · Mathematics 2007-05-23 H. Murat Tuncali , Vesko Valov

In this paper, we generalize the concept of unbounded norm (un) convergence: let $X$ be a normed lattice and $Y$ a vector lattice such that $X$ is an order dense ideal in $Y$; we say that a net $(y_\alpha)$ un-converges to $y$ in $Y$ with…

Functional Analysis · Mathematics 2017-10-25 M. Kandić , H. Li , V. G. Troitsky

The problem of characterizing normed ordered spaces which admit a representation in the algebraic, order and norm sense as a subspace of $C(X)$, the space of all continuous functions on a compact Hausdorff space is a classical problem that…

Functional Analysis · Mathematics 2026-03-30 Serdar Ay
‹ Prev 1 2 3 10 Next ›