Banach空间中的有界算子4子空间系统OACSTPCD

This paper studies the bounded operator four subspaces systems ST in Banach spaces.It shows that ST and ST'are isomorphic if and only if T and T'are similar.It also shows that ST is indecomposable if and only if T is strongly irreducible.Finally,it shows that when the conjugate space X*of Banach space X is w*separable,there is an uncountable family of indecomposable bounded operator four subspace systems in X ⊕ X which are not isomorphic each other.These results are the generalizations and supplements of the corresponding results on Hilbert spaces to Banach spaces.