George Mackey is an American mathematician, working mainly in the fields of representation theory and group actions, and related parts of functional analysis. He is also one of the pioneer writers on quantum logic, and noncommutative geometry. He has written substantial surveys connecting his research interests with a large body of mathematics.
Mackey's theorem is a result on the structure of induced representations when restricted to a subgroup, in terms of double cosets. It may be stated for finite groups, but has far-reaching extensions. Mackey theory , on representations of semidirect products, and the idea of Mackey functors , have become standard tools.