Birthdate: June 13, 1966

Sun Sign: Gemini

Birthplace: Saint Petersburg, Russia

Russian mathematician Grigori Perelman is best known for his work on geometry, especially Riemannian geometry, geometric analysis, and geometric topology. He declined many prizes, such as the Fields Medal and the Millennium Prize. His proof of the Poincaré conjecture was named the Breakthrough of the Year by Science magazine.