Lorenzo Molena, Università di Verona

Arrow-determined congruences and forcing ideals of Hasse quivers

Abstract:
We give a brief summary of the necessary prerequisites of lattice theory, in particular defining lattice congruences and recalling their properties.
Next we define the hasse quiver of a lattice L and describe a natural lattice structure on the set of its forcing ideals, ideal (Hasse L).
Successively, we introduce some interesting kinds of lattices and lattice congruences, namely the weakly atomic lattices, the completely semidistributive bialgebraic lattices, and the arrow-determined congruence relations.
Finally we prove that a complete congruence Θ on a complete lattice L is arrow determined iff L/Θ is weakly atomic, and we give a sketch of the proof of the isomorphism Conᶜᵃ L  ideal(Hasse L), where Conᶜᵃ L is the lattice of complete arrow-determined congruence relations, and L is a completely semidistributive lattice.

Reference:
Laurent Demonet, Osamu Iyama, Nathan Reading, Idun Reiten, and Hugh Thomas. Lattice theory of torsion classes: Beyond τ-tilting theory. Transactions of the American Mathematical Society, Series B, 2023,
542–612 .