Bloch's theorem

Etymology 1
Named after the physicist Felix Bloch.

Proper noun

 * 1)  A theorem stating that the energy eigenstates for an electron in a crystal can be written as Bloch waves.

Etymology 2
Named after the French mathematician André Bloch.

Proper noun

 * 1)  A theorem that gives a lower bound on the size of a disc in which an inverse to a holomorphic function exists.