Lookup NU author(s): Professor Guyan Robertson
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Let X be a finite connected graph, each of whose vertices has degree at least three. The fundamental group Γ of X is a free group and acts on the universal covering tree Δ and on its boundary ∂Δ, endowed with a natural topology and Borel measure. The crossed product C*-algebra C(∂Δ) ⋊ Γ depends only on the rank of Γ and is a Cuntz-Krieger algebra whose structure is explicitly determined. The crossed product von Neumann algebra does not possess this rigidity. If X is homogeneous of degree q + 1 then the von Neumann algebra L∞ (∂Δ) ⋊ Γ is the hyperfinite factor of type IIIλ where λ = 1/q2 if X is bipartite, and λ = 1/q otherwise. © 2005 University of Houston.
Author(s): Robertson G
Publication type: Article
Publication status: Published
Journal: Houston Journal of Mathematics
Print publication date: 01/01/2005
ISSN (print): 0362-1588
Publisher: University of Houston