摘要

Let D be any division ring with an involution, de,, (D) be the space of all n x n hermitian matrices over D. Two hermitian matrices A and B are said to be adjacent if rank(A - B) = 1. It is proved that if W is a bijective map from H,(D)(n >= 2) to itself such that phi preserves the adjacency, then phi(-1) also preserves the adjacency. Moreover, if H-n(D) not equal phi(3)(F-2), then W preserves the arithmetic distance. Thus, an open problem posed by Wan Zhe-Xian is answered for geometry of symmetric and hermitian matrices.