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): Alex Bowman • Américo Gallego • Jerry Barber • Joel Brand • John McFall (athlete) • Jonathan Bailey • Meadowlark Lemon • Melissa Hayden (dancer) • Mort Weisinger • Tony Phillips

Born in the same month (April 1849): William R. Day