Twisted cyclic theory, equivariant KK theory and KMS States
| dc.creator | Carey, Alan L. | |
| dc.creator | Neshveyev, Sergey | |
| dc.creator | Nest, Ryszard | |
| dc.creator | Rennie, Adam | |
| dc.date | 2008-08-22 | |
| dc.date.accessioned | 2026-07-07T09:57:55Z | |
| dc.date.available | 2026-07-07T09:57:55Z | |
| dc.description | Recently, examples of an index theory for KMS states of circle actions were discovered, \cite{CPR2,CRT}. We show that these examples are not isolated. Rather there is a general framework in which we use KMS states for circle actions on a C*-algebra A to construct Kasparov modules and semifinite spectral triples. By using a residue construction analogous to that used in the semifinite local index formula we associate to these triples a twisted cyclic cocycle on a dense subalgebra of A. This cocycle pairs with the equivariant KK-theory of the mapping cone algebra for the inclusion of the fixed point algebra of the circle action in A. The pairing is expressed in terms of spectral flow between a pair of unbounded self adjoint operators that are Fredholm in the semifinite sense. A novel aspect of our work is the discovery of an eta cocycle that forms a part of our twisted residue cocycle. To illustrate our theorems we observe firstly that they incorporate the results in \cite{CPR2,CRT} as special cases. Next we use the Araki-Woods III_λrepresentations of the Fermion algebra to show that there are examples which are not Cuntz-Krieger systems. | |
| dc.description | 29 pages | |
| dc.identifier | https://arxiv.org/abs/0808.3029 | |
| dc.identifier | http://arxiv.org/abs/0808.3029 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/167522 | |
| dc.subject | Operator Algebras | |
| dc.subject | K-Theory and Homology | |
| dc.title | Twisted cyclic theory, equivariant KK theory and KMS States | |
| dc.type | text |