Quantum stochastic processes for maps on Hilbert C*-modules

Abstract

We discuss pairs (phi, Phi) of maps, where phi is a map between C*-algebras and Phi is a phi-module map between Hilbert C*-modules, which are generalization of representations of Hilbert C*-modules. A covariant version of Stinespring's theorem for such a pair (phi, Phi) is established, and quantum stochastic processes constructed from pairs ({phi(t)}, {Phi(t)}) of families of such maps are studied. We prove that the quantum stochastic process J = {J(t)} constructed from a phi-quantum dynamical semigroup Phi = {Phi(t)} is a j-map for the quantum stochastic process j = {j(t)} constructed from the given quantum dynamical semigroup phi = {phi(t)}, and that J is covariant if the phi-quantum dynamical semigroup Phi is covariant.