# A Polish group containing a Haar null $F_\sigma$-subgroup that cannot be enlarged to a Haar null $G_\delta$-set

@article{Banakh2016APG,
title={A Polish group containing a Haar null \$F\_\sigma\$-subgroup that cannot be enlarged to a Haar null \$G\_\delta\$-set},
author={Taras O. Banakh},
journal={arXiv: General Topology},
year={2016}
}
• T. Banakh
• Published 1 April 2016
• Mathematics
• arXiv: General Topology
Answering a question of Elekes and Vidny\'anszky, we construct a Polish meta-abelian group $H$ and a subgroup $F\subset H$, which is a Haar null $F_\sigma$-set in $H$ that cannot be enlarged to a Haar null $G_\delta$-set.
1 Citations
Haar null and Haar meager sets: a survey and new results
• Mathematics
Bulletin of the London Mathematical Society
• 2020
We survey results about Haar null subsets of (not necessarily locally compact) Polish groups. The aim of this paper is to collect the fundamental properties of the various possible definitions of

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• Mathematics
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