Ultrafilters on balleans

  • I. V. Protasov Kyiv Nat. Taras Shevchenko Univ.
  • S. V. Slobodianiuk


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 terms of companions.
How to Cite
ProtasovI. V., and SlobodianiukS. V. “Ultrafilters on Balleans”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 67, no. 12, Dec. 2015, pp. 1698-06, http://umj.imath.kiev.ua/index.php/umj/article/view/2102.
Research articles