Möbius group

Etymology
Eponymous for August Ferdinand Möbius (1790–1868), a German mathematician and theoretical astronomer.

Noun

 * 1)  The projective general linear group $$\mathbf{PGL}(2,\mathbb{C})$$: the group of Möbius transformations on the Riemann sphere.
 * 2)  For a given dimension n, the group of projective transformations leaving a particular hypersphere invariant.

Translations

 * Dutch: Möbius-groep
 * Spanish: grupo de Möbius