Letαbe a flow on a Banach algebra B, and t 7→ut a continuous function from R into the group of invertible elements of B such that usαs(ut)=us+t, s, t∈R. Then βt =Adut?αt, t∈R is also a flow on B, where Adut...Letαbe a flow on a Banach algebra B, and t 7→ut a continuous function from R into the group of invertible elements of B such that usαs(ut)=us+t, s, t∈R. Then βt =Adut?αt, t∈R is also a flow on B, where Adut(B) , utBu-1t for any B ∈ B. β is said to be a cocycle perturbation of α. We show that if α, β are two flows on a nest algebra (or quasi-triangular algebra), thenβ is a cocycle perturbation ofα. And the flows on a nest algebra (or quasi-triangular algebra) are all uniformly continuous.展开更多
文摘Letαbe a flow on a Banach algebra B, and t 7→ut a continuous function from R into the group of invertible elements of B such that usαs(ut)=us+t, s, t∈R. Then βt =Adut?αt, t∈R is also a flow on B, where Adut(B) , utBu-1t for any B ∈ B. β is said to be a cocycle perturbation of α. We show that if α, β are two flows on a nest algebra (or quasi-triangular algebra), thenβ is a cocycle perturbation ofα. And the flows on a nest algebra (or quasi-triangular algebra) are all uniformly continuous.