Shing-Tung Yau won the Fields Medal while holding no passport at all
In 1982 Shing-Tung Yau became the first ethnic Chinese mathematician to win the Fields Medal. He accepted it officially stateless, his Hong Kong residency revoked and American citizenship still eight years away. His geometry went on to shape string theory, general relativity and the very idea of hidden extra dimensions.
Yau came into the world in Shantou in 1949, the fifth of eight children of Hakka parents; his father, Chen Ying Chiu, was a Kuomintang scholar of philosophy and economics. When he was a few months old the family fled the Communist takeover for British Hong Kong, where he was schooled in Cantonese. They had lost everything, and when Yau was thirteen his father and a sister died. He turned to his father's books and to schoolwork, then from 1966 read mathematics at a Hong Kong university, the Chinese University, leaving early without a degree.
In 1969 he started a doctorate at Berkeley. Over his first winter break he devoured early issues of the Journal of Differential Geometry and was inspired by John Milnor's papers, which led him to generalise Preissman's theorem. He finished his doctorate in 1971 under Shiing-Shen Chern. Posts followed at the Institute for Advanced Study, Stony Brook, Stanford and San Diego before Harvard in 1987. He retired from Harvard in 2022 and moved to Tsinghua University, where he directs a mathematical sciences centre bearing his name.
The Fields Medal honoured his work on partial differential equations, the Monge-Ampère equation, the positive energy theorem and, most famously, the Calabi conjecture, whose solution gave its name to Calabi-Yau manifolds. Many results came with collaborators such as Richard Schoen and Karen Uhlenbeck. William Thurston wrote in 1981 that one mathematician's work had rarely redirected whole fields so quickly. His ideas reach into mirror symmetry and algebraic geometry.
Yau became stateless in 1978, when the British consulate withdrew his Hong Kong residency over his American permanent residency, and stayed so until 1990. He later became a formidable builder of institutions in China and Hong Kong, founding the Institute of Mathematical Sciences in 1993 and proposing the International Congress of Chinese Mathematicians, first held in 1998. By 2021 he had advised more than seventy doctoral students.
Source: Shing-Tung Yau
