Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6424727 | Topology and its Applications | 2013 | 7 Pages |
Abstract
Let G be a countably infinite group. A topology on G is left invariant if left translations are continuous. A left invariant topology is strongly complete if it is regular and for every partition {Un:n<Ï} of G into open sets, there is a neighborhood V of 1 such that for every xâG, {n<Ï:(xV)â©Unâ â } is finite. We show that assuming MA, for every nâN, there is a strongly complete left invariant topology T on G with exactly n nonprincipal ultrafilters converging to 1, and in the case G=â¨ÏZ2, T can be chosen to be a group topology. We also show that it is consistent with ZFC that if G can be embedded algebraically into a compact group, then there are no such topologies on G.
Related Topics
Physical Sciences and Engineering
Mathematics
Geometry and Topology
Authors
Valentin Keyantuo, Yevhen Zelenyuk,