Eigensystem[] for higher dimensions?

*To*: mathgroup at smc.vnet.net*Subject*: [mg68472] Eigensystem[] for higher dimensions?*From*: AES <siegman at stanford.edu>*Date*: Sun, 6 Aug 2006 02:57:13 -0400 (EDT)*Organization*: Stanford University*Sender*: owner-wri-mathgroup at wolfram.com

Can the matrix m in Eigensystem[m] be greater than two dimensional? And the eigenvectors v correspondingly greater than one dimensional? The problem of interest is finding the eigenvalues lambda and eigenarrays A of the equation M A = lambda A with A being a (physically nonseparable) two dimensional array and M a specified four dimensional array. I can of course use appropriate indexing to convert these to one and two dimensional quantities, but the index transformations can be a pain; the reverse index transformations even more ugly; the Mathematica Book doesn't seem to explicitly answer the question -- and it's easier to ask it here, and maybe also get some useful pointers, than futz around with experiments.