The Mackey Quotient Groupoid
by
John Quigg
Arizona State University
Coauthors: Magnus Landstad (University of Trondheim)

An important tool in the representation theory of groups is to relate the representations of a group G to those of a subgroup H. When the subgroup H is normal, the quotient G/H is again a group, and there is a very satisfactory theory relating the representations of G, H, and G/H. We will associate to any subgroup H what we call the ``Mackey quotient groupoid'', which reduces to the usual quotient group when H is normal. Our primary motivation for introducing the quotient groupoid is to get a ``Mackey machine'' for coactions on C^*-algebras, and we indicate (very) preliminary progress toward this goal.

Date received: May 1, 1999