Browse by author
Lookup NU author(s): Professor Guyan Robertson
Let Γ be a torsion-free cocompact lattice in Aut(T1) × Aut(T2), where T1, T2 are trees whose vertices all have degree at least three. The group H2 (Γ, ℤ) is determined explicitly in terms of an associated 2-dimensional tiling system. It follows that under appropriate conditions the crossed product C* -algebra A associated with the action of Γ on the boundary of T1 × T2 satisfies rank Ko(A) = 2 · rank H2(Γ,ℤ).
Author(s): Robertson G
Publication type: Article
Publication status: Published
Journal: New York Journal of Mathematics
Year: 2005
Volume: 11
Pages: 635-647
ISSN (print): 1076-9803
ISSN (electronic):
Publisher: Electronic Journals Project
URL: http://nyjm.albany.edu/j/2005/11-29.pdf