DETERMINATION OF JORDAN CHAINS BY EXTENDED MATRICES

The major obstacle to determination of the Jordan chains for a highly degenerated eigenproblem is that the triangular combinations of the pr incipal vectors in a Jordan chain are also principal vectors and the l inear combinations of the eigenvectors of all Jordan blocks associated with the same eigenvalue are also eigenvectors. These indeterminate c onstants will hide the Jordan block structure and make the analysis ve ry difficult. We propose an extended matrix method to find the Jordan chains and eliminate the indeterminate constants so that the Jordan bl ock structure can be computed sequentially. An example with the Segre characteristic [(321)11] is given. (C) 1998 John Wiley & Sons, Ltd.