Mathematics and physics often have deep, unexpected connections. I will first introduce observed phenomena of gravitational lensing, its applications to the study of extrasolar planets and dark matter, and then discuss how gravitational lensing is connected to the branch of mathematics: catastrophe theory.

Professor of Astrophysics and Chair of the Department of Astronomy, Tsinghua University. Prof. Shude Mao is mainly interested in the search of extrasolar planets, gravitational lensing and galactic dynamics.