Dense Subspaces of Some Spaces of Continuous Functions.
Homeomorphs of Three Subspaces of ß NN.
Homogeneity and rigidity in Erdös spaces
The classical Erdös spaces are obtained as the subspaces of real separable Hilbert space consisting of the points with all coordinates rational or all coordinates irrational, respectively. One can create variations by specifying in which set each coordinate is allowed to vary. We investigate the homogeneity of the resulting subspaces. Our two main results are: in case all coordinates are allowed to vary in the same set the subspace need not be homogeneous, and by specifying different sets for different...
Large families of dense pseudocompact subgroups of compact groups
We prove that every nonmetrizable compact connected Abelian group G has a family H of size |G|, the maximal size possible, consisting of proper dense pseudocompact subgroups of G such that H ∩ H'={0} for distinct H,H' ∈ H. An easy example shows that connectedness of G is essential in the above result. In the general case we establish that every nonmetrizable compact Abelian group G has a family H of size |G| consisting of proper dense pseudocompact subgroups of G such that each intersection H H'...
Left-separated spaces: a comment to a paper of M. G. Tkačenko
Metrizable subsets of Moore spaces
More on -Ohio completeness
We study closed subspaces of -Ohio complete spaces and, for uncountable cardinal, we prove a characterization for them. We then investigate the behaviour of products of -Ohio complete spaces. We prove that, if the cardinal is endowed with either the order or the discrete topology, the space is not -Ohio complete. As a consequence, we show that, if is less than the first weakly inaccessible cardinal, then neither the space , nor the space is -Ohio complete.
More on -closed sets in topological spaces.
Narrow spaces, products of topological spaces and supertiny sequences of A. Szymański
New approach for closure spaces by relations.
Non-normality and relative normality of Niemytzki plane
Non-separating subcontinua of planar continua
We revisit an old question of Knaster by demonstrating that each non-degenerate plane hereditarily unicoherent continuum X contains a proper, non-degenerate subcontinuum which does not separate X.
Numerical invariants of 0-dimensional spaces and their Cartesian multiplication.
On continuous images of almost Tychonoff cubes
On dense subspaces of certain topological spaces
On and weakly- spaces.
On PSigma and Weakly PSigma Spaces
On some maps concerning -open sets.
On some subspaces of the Helly space
On subspaces of pseudo-radial spaces
It is proved that, under the Martin’s Axiom, every -space with countable tightness is a subspace of some pseudo-radial space. We also give several characterizations of subspaces of pseudo-radial spaces and conclude that being a subspace of a pseudo-radial space is a local property.