Eugène Ehrhart

Eugène Ehrhart (29 April 1906 – 17 January 2000) was a French mathematician who in the 1960s introduced Ehrhart polynomials, which count the lattice points in a polytope with integral vertices, their reciprocity property, and their generalization to rational polytopes. Ehrhart received his high school diploma at the age of 22. He was a mathematics teacher in several high schools, and did mathematics research on his own time. He started publishing in mathematics in his 40s, and finished his PhD thesis at the age of 60.