Dominance and equivalence for states on $C^*$-algebras: Quasi-Invariant states
We study the noncommutative generalization of measure-theoretic dominance and equivalence of states on $C^*$-algebras to explore quasi-invariance under group actions. For a dominated state, we derive an unbounded"Radon-Nikodym"derivative affiliated with the commutant algebra of the dominating state's GNS representation...