Felix Klein
Felix Christian Klein was a German mathematician and mathematics educator, known for his work in group theory, complex analysis, non-Euclidean geometry, and the associations between geometry and group theory. His 1872 Erlangen program classified geometries by their basic symmetry groups and was an influential synthesis of much of the mathematics of the time.
25 April 1849
Born on the same birth day (25 April): Abdalla Uba Adamu • Albert King • Breyton Paulse • C. B. Fry • Claudia Salman • Daniel Kash • Dominique Blanc • James Sheppard • Johnny Craig • Monty Panesar • RaphaĆ«l Varane • Robert Skidelsky • Roger Boisjoly • Thomas Strunz • Vladislav Tretiak
Born in the same month (April 1849): William R. Day