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JOURNALS // Russian Universities Reports. Mathematics // Archive

Russian Universities Reports. Mathematics, 2020 Volume 25, Issue 129, Pages 68–84 (Mi vtamu171)

This article is cited in 1 paper

Scientific articles

Maximal linked systems and ultrafilters: main representations and topological properties

A. G. Chentsovab

a N.N. Krasovskii Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences
b Ural Federal University named after the first President of Russia B.N. Yeltsin

Abstract: Questions connected with representation of the ultrafilter (UF) set for widely understood measurable space are investigated; this set is considered as a subspace of bitopological space of maximal linked systems (MLS) under equipment with topologies of Wallman and Stone types (measurable structure is defined as a $\pi$-system with “zero” and “unit”). Analogous representations connected with generalized variant of cohesion is considered also; in this variant, for corresponding set family, it is postulated the nonemptyness of intersection for finite subfamilies with power not exceeding given. Conditions of identification of UF and MLS (in the above-mentioned generalized sense) are investigated. Constructions reducing to bitopological spaces with points in the form of MLS and $n$-supercompactness property generalizing the “usual” supercompactness are considered. Finally, some characteristic properties of MLS and their corollaries connected with the MLS contraction to a smaller \linebreak$\pi$-system are being studied. The case of algebras of sets is selected separately.

Keywords: bitopological space, maximal linked system, ultrafilter.

UDC: 519.6

Received: 16.01.2020

DOI: 10.20310/2686-9667-2020-25-129-68-84



© Steklov Math. Inst. of RAS, 2025