Ultrafilters on balleans

• Published in: Український математичний журнал
• Date: 2015
• ISSN: 1027-3190
• Main Authors: Protasov, I.V., Slobodianiuk, S.V.
• Format: Article
• Language: English
• Published: Інститут математики НАН України 2015
• Subjects: Статті
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/165924
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Ultrafilters on balleans / I.V. Protasov, S.V. Slobodianiuk // Український математичний журнал. — 2015. — Т. 67, № 12. — С. 1698–1706. — Бібліогр.: 18 назв. — англ.

A ballean (equivalently, a coarse structure) is an asymptotic counterpart of a uniform space. We introduce three ultrafilter satellites of a ballean (namely, corona, companion, and corona companion), evaluate the basic cardinal invariants of the corona and characterize the subsets of balleans in ter...