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JOURNALS // Moscow Mathematical Journal // Archive

Mosc. Math. J., 2022 Volume 22, Number 2, Pages 295–372 (Mi mmj829)

Congruences on infinite partition and partial Brauer monoids

James Easta, Nik Ruškucb

a Centre for Research in Mathematics, School of Computing, Engineering and Mathematics, Western Sydney University, Locked Bag 1797, Penrith NSW 2751, Australia
b Mathematical Institute, School of Mathematics and Statistics, University of St Andrews, St Andrews, Fife KY16 9SS, UK

Abstract: We give a complete description of the congruences on the partition monoid $\mathcal{P}_X$ and the partial Brauer monoid $\mathcal{PB}_X$, where $X$ is an arbitrary infinite set, and also of the lattices formed by all such congruences. Our results complement those from a recent article of East, Mitchell, Ruškuc and Torpey, which deals with the finite case. As a consequence of our classification result, we show that the congruence lattices of $\mathcal{P}_X$ and $\mathcal{PB}_X$ are isomorphic to each other, and are distributive and well quasi-ordered. We also calculate the smallest number of pairs of partitions required to generate any congruence; when this number is infinite, it depends on the cofinality of certain limit cardinals.

Key words and phrases: diagram monoids, partition monoids, partial Brauer monoids, congruences, well quasi-orderedness.

MSC: 20M20, 08A30, 06A06, 03E04

Language: English



© Steklov Math. Inst. of RAS, 2024