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

Abstract

Answering a question of Elekes and Vidnyánszky, 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.

arXiv comment2 pages

Cited by in corpus (1)

• Different Hamiltonians for differential Painlevé equations and their identification using a geometric approach