Descriptive complexity of the sizes of subsets of groups

• Datum: 2017
• Hauptverfasser: Banakh, T. O., Protasov, I. V., Protasova, K. D., Банах, Т. О., Протасов, І. В., Протасова, К. Д.
• Format: Artikel
• Sprache: Ukrainisch
• Veröffentlicht: Institute of Mathematics, NAS of Ukraine 2017
• Online Zugang: https://umj.imath.kiev.ua/index.php/umj/article/view/1780
• Назва журналу: Ukrains’kyi Matematychnyi Zhurnal

We study the Borel complexity of some basic families of subsets of a countable group (large, small, thin, rarefied, etc.) determined by the sizes of their elements. The obtained results are applied to the Czech – Stone compactification $\beta G$ of the group $G$. In particular, it is shown that the...