The graphs of join-semilattices and the shape of congruence lattices of particle lattices

Růžička, Pavel

Commentationes Mathematicae Universitatis Carolinae, Tome 58 (2017) no. 3, pp. 275-291.

Résumé

We attach to each $\langle 0,\vee \rangle$-semilattice $\boldsymbol S$ a graph $\boldsymbol G_{\boldsymbol S}$ whose vertices are join-irreducible elements of $\boldsymbol S$ and whose edges correspond to the reflexive dependency relation. We study properties of the graph $\boldsymbol G_{\boldsymbol S}$ both when $\boldsymbol S$ is a join-semilattice and when it is a lattice. We call a $\langle 0,\vee \rangle$-semilattice $\boldsymbol S$ particle provided that the set of its join-irreducible elements satisfies DCC and join-generates $\boldsymbol S$. We prove that the congruence lattice of a particle lattice is anti-isomorphic to the lattice of all hereditary subsets of the corresponding graph that are closed in a certain zero-dimensional topology. Thus we extend the result known for principally chain finite lattices.

Détail

DOI : 10.14712/1213-7243.2015.214

Classification : 06A12, 06A15, 06B10, 06F30
Keywords: join-semilattice; lattice; join-irreducible; dependency; chain condition; particle; atomistic; congruence