KMS weights on graph C*-algebras II Factor types and ground states

TL;DR

This paper classifies the types of factors arising from extremal KMS weights and describes ground states for generalized gauge actions on graph C*-algebras, extending previous results to broader graph classes.

Contribution

It extends the analysis of KMS weights on graph C*-algebras to include factor types and ground states under more general conditions.

Findings

Determined factor types of extremal KMS weights.

Characterized ground states for restricted gauge actions.

Covered graphs with countably many exits and strong connectivity.

Abstract

We determine the factor types of the extremal KMS weights for generalized gauge actions on a graph algebra, and the ground states for the restriction of the action to a corner defined from a vertex. The assumptions on the graph and the action varies a bit, but they all cover, at the very least, the case of the gauge action on a strongly connected graph with at most countably many exits. These are the graphs for which all the KMS weights of the gauge action were determined in the first part of this work.