Shing-Tung Yau (/jaʊ/; Chinese: 丘成桐; pinyin: Qiū Chéngtóng; born April 4, 1949) is an American mathematician and the William Caspar Graustein Professor of Mathematics at Harvard University. Yau was born in Shantou, China, moved to Hong Kong at a young age, and to the United States in 1969. He was awarded the Fields Medal in 1982, in recognition of his contributions to partial differential equations, the Calabi conjecture, the positive energy theorem, and the Monge–Ampère equation. Yau is considered as one of the major contributors to the development of modern differential geometry and geometric analysis.The impact of Yau's work can be seen in the mathematical and physical fields of differential geometry, partial differential equations, convex geometry, algebraic geometry, enumerative geome