I am constantly working with hermitian matrices without multiplicity in their spectrum. Since this hypothesis appear in several important problems, for instance perturbation theory, I looked in the literature for an accepted terminology but found nothing. Does anyone know a reference where these matrices, or their set, have been given a name ? I am considering calling them "simple matrices" but it is a bit ambiguous...



A name for matrices with only simple eigenvalues?
Since your matrices are Hermitian, this is the same as *non-derogatory* ... see <http://en.wikipedia.org/wiki/List_of_matrices> for terminology *derogatory matrix*.


