Herglotz-Noether theorem

Etymology
Formulated by Gustav Herglotz (1909) and in a less general way by Fritz Noether (1909).

Proper noun

 * 1)  A theorem stating that all irrotational Born rigid motions (class A) consist of hyperplanes rigidly moving through spacetime, while any rotational Born rigid motion (class B) must be an isometric Killing motion, and thus a Born rigid body only has three degrees of freedom.