TY - JOUR
T1 - Symmetries of the KMS Simplex
AU - Christensen, Johannes
PY - 2018/11/1
Y1 - 2018/11/1
N2 - A continuous groupoid homomorphism c on a locally compact second countable Hausdorff étale groupoid G gives rise to a C*-dynamical system in which every β-KMS state can be associated to a e-
β
c-quasi-invariant measure μ on G(0). Letting Δ μ denote the set of KMS states associated to such a μ, we will prove that Δ μ is a simplex for a large class of groupoids, and we will show that there is an abelian group that acts transitively and freely on the extremal points of Δ μ. This abelian group can be described using the support of μ, so our theory can be used to obtain a description of all KMS states by describing the e-
β
c-quasi-invariant measures. To illustrate this we will describe the KMS states for the Cuntz–Krieger algebras of all finite higher rank graphs without sources and a large class of continuous one-parameter groups.
AB - A continuous groupoid homomorphism c on a locally compact second countable Hausdorff étale groupoid G gives rise to a C*-dynamical system in which every β-KMS state can be associated to a e-
β
c-quasi-invariant measure μ on G(0). Letting Δ μ denote the set of KMS states associated to such a μ, we will prove that Δ μ is a simplex for a large class of groupoids, and we will show that there is an abelian group that acts transitively and freely on the extremal points of Δ μ. This abelian group can be described using the support of μ, so our theory can be used to obtain a description of all KMS states by describing the e-
β
c-quasi-invariant measures. To illustrate this we will describe the KMS states for the Cuntz–Krieger algebras of all finite higher rank graphs without sources and a large class of continuous one-parameter groups.
UR - http://www.scopus.com/inward/record.url?scp=85053705637&partnerID=8YFLogxK
U2 - 10.1007/s00220-018-3250-5
DO - 10.1007/s00220-018-3250-5
M3 - Journal article
AN - SCOPUS:85053705637
SN - 0010-3616
VL - 364
SP - 357
EP - 383
JO - Communications in Mathematical Physics
JF - Communications in Mathematical Physics
IS - 1
ER -