TITLE: A name for matrices with only simple eigenvalues?
QUESTION [6 upvotes]: 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...

REPLY [6 votes]: Apparently, there is something I don't understand in this discussion. Why should one reinvent the wheel? Such matrices have always been known as Hermitian matrices with simple spectrum. Just look at this wiktionary entry or Terry Tao's blog out of thousands of other examples.