bobm@ee.rochester.edu (Bob Molyneaux) (11/29/89)
Hi All, A square matrix A is said to be nilpotent if A^k = 0 for some value of k. A square matrix A is said to be idempotent if A^2 = A ==> A^k = A for all values of k. Is there a classification for the square matrix A for which A^k = A for not all but some value(s) of k? Please email resonses along with references. (Subject references not yours!) Thanks bobm.ee.rochester.edu