Duality theory for covariant systems

If ( A , ρ , G ) (A,ρ ,G) is a covariant system over a locally compact group G , i.e. ρ ρ is a homomorphism from G into the group of ∗ -automorphisms of an operator algebra A , there is a new operator algebra A A called the covariance algebra associated with ( A , ρ , G ) (A,ρ ,G) . If A is a von Neumann algebra and ρ ρ is σ σ -weakly continuous, A A is defined such that it is a von Neumann algebra. If A is a C ∗ {C} -algebra and ρ ρ is norm-continuous A A will be a C ∗ {C} -algebra. The following problems are studied in these two different settings: 1. If A <mml:annotation enco