40 research outputs found
Products of finite groups and nonmeasurable subgroups
It is proven that if is a finite group, then has dense nonmeasurable subgroups. Also, other examples of compact groups with
dense nonmeasurable subgroups are presented.Comment: 5 page
When a totally bounded group topology is the Bohr Topology of a LCA group
We look at the Bohr topology of maximally almost periodic groups (MAP, for
short). Among other results, we investigate when a totally bounded abelian
group is the Bohr reflection of a locally compact abelian group.
Necessary and sufficient conditions are established in terms of the inner
properties of . As an application, an example of a MAP group is
given such that every closed, metrizable subgroup of with preserves compactness but does not strongly respects
compactness. Thereby, we respond to Questions 4.1 and 4.3 in [comftrigwu]
Contributions to the Bohr topology by W.W. Comfort
The important rôle that W. W. Comfort played in the study of the Bohr topology is described
Locally pseudocompact topological groups
AbstractA topological group is said to be locally pseudocompact if the identity has a pseudocompact neighborhood (equivalently: if the identity has a local basis of pseudocompact neighborhoods). Such groups are locally bounded in the sense of A. Weil, so each such group G is densely embedded in an essentially unique locally compact group G (called its Weil completion). The authors present necessary and sufficient conditions of local and global nature for a locally bounded group to be locally pseudocompact, as follows. Theorem. If G is a locally bounded group with Weil completionG, then the following conditions are equivalent: 1.(i) Gis locally pseudocompact;2.(ii) G is C∗-embedded in G (i.e., βG = βG);3.(iii) G is C-embedded in G (i.e., υG = υG);4.(iv) G is M-embedded in G (i.e., γG = G);5.(v) some nonempty open subsetU of G satisfies β(clGU) = clGU;6.(vi) every bounded open subset U of G satisfies β(clGU) = clGU
Weakly pseudocompact subsets of nuclear groups
Let G be an Abelian topological group and G(+) the group G endowed with the weak topology induced by continuous characters. We say that G respects compactness (pseudocompactness, countable compactness, functional boundedness) if G and G+ have the same compact (pseudocompact, countably compact, functionally bounded) sets. The well-known theorem of Glicksberg that LCA groups respect compactness was extended by Trigos-Arrieta to pseudocompactness and functional boundedness. In this paper we generalize these results to arbitrary nuclear groups, a class of Abelian topological groups which contains LCA groups and nuclear locally convex spaces and is closed with respect to subgroups, separated quotients and arbitrary products