Complements in the lattice of all topologies of topological groups
We present an example of a complete -bounded topological group which is not -factorizable. In addition, every -set in the group is open, but is not Lindelöf.
Let be a Tychonoff (regular) paratopological group or algebra over a field or ring or a topological semigroup. If and , then there exists a Tychonoff (regular) topology such that and is a paratopological group, algebra over or a topological semigroup respectively.
We prove that every connected locally compact Abelian topological group is sequentially connected, i.e., it cannot be the union of two proper disjoint sequentially closed subsets. This fact is then applied to the study of extensions of topological groups. We show, in particular, that if is a connected locally compact Abelian subgroup of a Hausdorff topological group and the quotient space is sequentially connected, then so is .