This paper is devoted to perturbation analysis for the eigenproblem of peri
odic matrix pairs {(A(j), E-j)}(j=1)(K). We first study perturbation expans
ions of periodic deflating subspaces and eigenvalue pairs. Then, we derive
explicit expressions of condition numbers, perturbation bounds and backward
errors for eigenvalue pairs and periodic deflating subspaces. (C) 2001 Els
evier Science Inc. All rights reserved.