scholarly journals Continuous-trace groupoid crossed products

2003 ◽  
Vol 132 (3) ◽  
pp. 707-717 ◽  
Author(s):  
Igor Fulman ◽  
Paul S. Muhly ◽  
Dana P. Williams
2004 ◽  
Vol 76 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Paul S. Muhly ◽  
Dana P. Williams

AbstractWe give a formula for the Dixmier-Douady class of a continuous-trace groupoid crossed product that arises from an action of a locally trivial, proper, principal groupoid on a bundle of elementary C*-algebras that satisfies Fell's condition.


1996 ◽  
Vol 123 (586) ◽  
pp. 0-0 ◽  
Author(s):  
Siegfried Echterhoff

2014 ◽  
Vol 72 (2) ◽  
pp. 557-576 ◽  
Author(s):  
Erik van Erp ◽  
Dana P. Williams

1993 ◽  
Vol 45 (5) ◽  
pp. 1032-1066 ◽  
Author(s):  
Iain Raeburn ◽  
Dana P. Williams

AbstractContinuous-trace C*-algebras A with spectrum T can be characterized as those algebras which are locally Monta equivalent to C0(T). The Dixmier-Douady class δ(A) is an element of the Čech cohomology group Ȟ3(T, ℤ) and is the obstruction to building a global equivalence from the local equivalences. Here we shall be concerned with systems (A, G, α) which are locally Monta equivalent to their spectral system (C0(T),G, τ), in which G acts on the spectrum T of A via the action induced by α. Such systems include locally unitary actions as well as N-principal systems. Our new Dixmier-Douady class δ (A, G, α) will be the obstruction to piecing the local equivalences together to form a Monta equivalence of (A, G, α) with its spectral system. Our first main theorem is that two systems (A, G, α) and (B, G, β) are Monta equivalent if and only if δ (A, G, α) = δ (B, G, β). In our second main theorem, we give a detailed formula for δ (A ⋊α G) when (A, G, α) is N-principal.


Sign in / Sign up

Export Citation Format

Share Document