Research on Some Properties of Sequential Product
Chunfang Shao · 2010
It is assumed that e(H) is the set of all positive contraction operators,and P(H) is the set of all orthogonal projections in Hilbert space H in this paper.Forthermore,A∈e(H) is called a quantum effect,called for short.If A,B∈e(H),A°B=A12BA12,is called the sequential product of effect A and B.By using the technique of operator block,the equivalent conditions of A°B∈P(H)when A,B∈e(H) or A,B∈P(H) are discussed respectively.Based on the theory of space decomposition,its geometry structure is further made more clear to be convenient to do research on its corresponding properties.