Compact spaces generated by retractions
Wieslaw Kubis
Abstract
We study compact spaces which are obtained from metric compacta by iterating the operation of inverse limit of continuous sequences of retractions. We denote this class by R. Allowing continuous images in the definition of class R, one obtains a strictly larger class, which we denote by RC. We show that every space in class RC is either Corson compact or else contains a copy of the ordinal segment [0,ω1]. This improves a result of Kalenda, where the same was proved for the class of continuous images of Valdivia compacta. We prove that spaces in class R do not contain cutting P-points (see the definition below), which provides a tool for finding spaces in RC minus R. Finally, we study linearly ordered spaces in class RC. We prove that scattered linearly ordered compacta belong to RC and we characterize those ones which belong to R. We show that there are only 5 types (up to order isomorphism) of connected linearly ordered spaces in class R and all of them are Valdivia compact. Finally, we find a universal pre-image for the class of all linearly ordered Valdivia compacta.
Create a lesson
Related papers
Ultrafilter characters and local π-bases
Jerzy Kcakol
Countable compactness is A-invariant
ZhouXiang Huang
The size of the poset of compatible locally quasi-convex topologies on locally compact abelian groups
ZhouXiang Huang
A Universal Quasi-Polish Space
Su Gao, Qingguo Li, Hualin Miao
Metrizable and Fréchet--Urysohn subgroups and linear subspaces of topological vector spaces
Arkady Leiderman, Evgenii Reznichenko, Ol'ga Sipacheva
Nonexpansive Bijections in T0-Quasi-Metric Spaces and Their q-Hyperconvex Hulls
Collins Amburo Agyingi