2024/05/30 by Bardyla, Serhii, Elliott, Luna, Mitchell, James +1
#20M18 #20M20 #22A15 #54E35 #54H15 #FOS: Mathematics #General Topology (math.GN) #Rings and Algebras (math.RA)
paper · doi:10.48550/arxiv.2405.20134
We classify all Polish semigroup topologies on the symmetric inverse monoid on the natural numbers. This result answers a question of Elliott et al. There are countably infinitely many such topologies. Under containment, these Polish semigroup topologies form a join-semilattice with infinite descending chains, no infinite ascending chains, and arbitrarily large finite anti-chains. Also, we show that the monoid endowed with any second countable T1 semigroup topology is homeomorphic to the Baire space.