On topological factors of 3 dimensional locally connected continuum embeddable in
On topological types of the simplest indecomposable continua
On topologies convexly compatible with the ordering
On transfinite dimension
On transfinite inductive compactness degree
On (transfinite) small inductive dimension of products
In this paper we study the behavior of the (transfinite) small inductive dimension on finite products of topological spaces. In particular we essentially improve Toulmin’s estimation [T] of for Cartesian products.
On treelike neighbourhood spaces
On treelike proximity spaces
On two theorems of Dyer
On uncountable collections of continua and their span
We prove that if the Euclidean plane contains an uncountable collection of pairwise disjoint copies of a tree-like continuum X, then the symmetric span of X is zero, sX = 0. We also construct a modification of the Oversteegen-Tymchatyn example: for each ε > 0 there exists a tree such that σX < ε but X cannot be covered by any 1-chain. These are partial solutions of some well-known problems in continua theory.
On uniquely arcwise connected curves
On universal infinite-dimensional spaces
On universality of countable and weak products of sigma hereditarily disconnected spaces
Suppose a metrizable separable space Y is sigma hereditarily disconnected, i.e., it is a countable union of hereditarily disconnected subspaces. We prove that the countable power of any subspace X ⊂ Y is not universal for the class ₂ of absolute -sets; moreover, if Y is an absolute -set, then contains no closed topological copy of the Nagata space = W(I,ℙ); if Y is an absolute -set, then contains no closed copy of the Smirnov space σ = W(I,0). On the other hand, the countable power of...
On universality of finite powers of locally path-connected meager spaces
It is shown that for every integer n the (2n+1)th power of any locally path-connected metrizable space of the first Baire category is 𝓐₁[n]-universal, i.e., contains a closed topological copy of each at most n-dimensional metrizable σ-compact space. Also a one-dimensional σ-compact absolute retract X is found such that the power X^{n+1} is 𝓐₁[n]-universal for every n.
On weakly infinite-dimensional subspuees
We will construct weakly infinite-dimensional (in the sense of Y. Smirnov) spaces X and Y such that Y contains X topologically and and . Consequently, the subspace theorem does not hold for the transfinite dimension dim for weakly infinite-dimensional spaces.
On weakly monotonically monolithic spaces
In this note, we introduce the concept of weakly monotonically monolithic spaces, and show that every weakly monotonically monolithic space is a -space. Thus most known conclusions on -spaces can be obtained by this conclusion. As a corollary, we have that if a regular space is sequential and has a point-countable -network then is a -space.
On weakly n-dimensional spaces
On weakly zero-dimensional mappings
On zero-dimensionality of subgroups of locally compact groups
Improving the recent result of the author we show that is equivalent to for every subgroup of a Hausdorff locally compact group .
On Δ-spaces and fundamental dimension in the sense of Borsuk