Coherence Invariant Mappings on Block Triangular Matrix Spaces

W.L. CHOOI AND M.H. LIM

Research Report No. 5/2001

Abstract

In this paper we classify bijective mappings $\psi$ on the space of block upper triangular matrices such that both $\psi$ and $\psi^{-1}$ preserve pairs of matrices whose differences have rank one. Applications to rank one preservers and semi-isomorphisms are considered.