  We use the generalized concurrence approach to investigate the general
multipartite separability problem. By extending the preconcurrence matrix
formalism to arbitrary multipartite systems, we show that the separability
problem can be formulated equivalently as a pure matrix analysis problem that
consists in determining whether a given set of symmetric matrices is
simultaneously unitarily congruent to hollow matrices, i.e., to matrices whose
main diagonal is only composed of zeroes.
