Speaker : Christof Külske
Title: On localized and delocalized infinite-volume states for gradient models on
trees
Abstract: We consider spin systems with gradient interactions on infinite regular
trees.
These are integer-valued spin-models, where the spins (also called height variables)
interact via a height-shift invariant interaction, between nearest neighbors on the
tree.
We construct different types of infinite-volume states:
States which localize at given finite heights, and more generally
states which localize on finite subsets A of the local state space.
We also discuss related existence results for delocalized states,
and show that they may coexist with the localized ones at the same parameter
values of the model, in regimes of low enough temperature.
Joint works
with Florian Henning, Alberto Abbondandolo, Pietro Majer, Arnaud Le Ny, Loren
Coquille, Utkir Rozikov.