Eigenvalue

*To*: mathgroup at smc.vnet.net*Subject*: [mg14170] Eigenvalue*From*: RENZONI_FERRUCCIO <RENZONI at physnet.uni-hamburg.de>*Date*: Wed, 30 Sep 1998 02:04:18 -0400*Sender*: owner-wri-mathgroup at wolfram.com

Dear MathUsers, I have a 9x9 real matrix M containing 3 parameters (say, s, g and b). I would like to find an analytic expression for the eigenvalues of M at the second order in the parameters s and g (the expansion is around s=0 and g=0). I tought to find the eigenvalue as Root objects and then to expand them in Taylor series. For some eigenvalue works fine, for some other not. I obviously verified numerically that all the eigenvalues exist and are finite. Are there other way to find eigenvalues at a given order in the parameters without using Root object? E-mail to me directly please. Thanks a lot, Ferruccio Renzoni