Baireness of for ordered
We show that if is a subspace of a linearly ordered space, then is a Baire space if and only if is Choquet iff has the Moving Off Property.
We show that if is a subspace of a linearly ordered space, then is a Baire space if and only if is Choquet iff has the Moving Off Property.
A topological space is called base-base paracompact (John E. Porter) if it has an open base such that every base has a locally finite subcover . It is not known if every paracompact space is base-base paracompact. We study subspaces of the Sorgenfrey line (e.g. the irrationals, a Bernstein set) as a possible counterexample.
Let X and Y be compacta and let f:X → Y be a k-dimensional map. In [5] Pasynkov stated that if Y is finite-dimensional then there exists a map such that dim (f × g) = 0. The problem that we deal with in this note is whether or not the restriction on the dimension of Y in the Pasynkov theorem can be omitted. This problem is still open. Without assuming that Y is finite-dimensional Sternfeld [6] proved that there exists a map such that dim (f × g) = 1. We improve this result of Sternfeld showing...
Borsuk's quasi-equivalence relation on the class of all compacta is considered. The open problem concerning transitivity of this relation is solved in the negative. Namely, three continua X, Y and Z lying in ℝ³ are constructed such that X is quasi-equivalent to Y and Y is quasi-equivalent to Z, while X is not quasi-equivalent to Z.
The Borsuk-Sieklucki theorem says that for every uncountable family of n-dimensional closed subsets of an n-dimensional ANR-compactum, there exist α ≠ β such that . In this paper we show a cohomological version of that theorem: Theorem. Suppose a compactum X is , where n ≥ 1, and G is an Abelian group. Let be an uncountable family of closed subsets of X. If for all α ∈ J, then for some α ≠ β. For G being a countable principal ideal domain the above result was proved by Choi and Kozlowski...