On certain Conjectures on invariant measures on semigroups.
On certain groups of functions.
On certain representation of topological groups.
On certain two generator monoids.
On characterized subgroups of Abelian topological groups and the group of all -valued null sequences
Let be an Abelian topological group. A subgroup of is characterized if there is a sequence in the dual group of such that . We reduce the study of characterized subgroups of to the study of characterized subgroups of compact metrizable Abelian groups. Let be the group of all -valued null sequences and be the uniform topology on . If is compact we prove that is a characterized subgroup of if and only if , where and is a finite Abelian group. For every compact Abelian...
On closed graph theorems in topological spaces and groups
ON COMPACT AFFINE SEMIGROUPS.
On compact locally connected semigroups with identity.
On compact -semigroups
On compact regular semigroups of complex matrices.
On compactification lattices of subsemigroups of .
On compactifying semigroups.
On compressed ideals in topological semigroups
On connected unars with regular endomorphism monoids
On convergence groupoids
On convergence groups
On convergence groups with dense coarse subgroups
On convergence spaces and groups
On coverings in the lattice of all group topologies of arbitrary Abelian groups.
On dense subspaces satisfying stronger separation axioms
We prove that it is independent of ZFC whether every Hausdorff countable space of weight less than has a dense regular subspace. Examples are given of countable Hausdorff spaces of weight which do not have dense Urysohn subspaces. We also construct an example of a countable Urysohn space, which has no dense completely Hausdorff subspace. On the other hand, we establish that every Hausdorff space of -weight less than has a dense completely Hausdorff (and hence Urysohn) subspace. We show that...