Meager-additive sets in topological groups
General Topology
2018-06-19 v1 Functional Analysis
Metric Geometry
Abstract
By the Galvin-Mycielski-Solovay theorem, a subset of the line has Borel's strong measure zero if and only if for each meager set . A set is meager-additive if is meager for each meager set . Recently a theorem on meager-additive sets that perfectly parallels the Galvin-Mycielski-Solovay theorem was proven: A set is meager-additive if and only if it has sharp measure zero, a notion akin to strong measure zero. We investigate the validity of this result in Polish groups. We prove, e.g., that a set in a locally compact Polish group admitting an invariant metric is meager-additive if and only if it has sharp measure zero. We derive some consequences and calculate some cardinal invariants.
Cite
@article{arxiv.1806.06674,
title = {Meager-additive sets in topological groups},
author = {Ondrej Zindulka},
journal= {arXiv preprint arXiv:1806.06674},
year = {2018}
}