ShingTung Yau
ShingTung Yau  

Born 
Shantou, Guangdong Province, China 
April 4, 1949
Residence  U.S. 
Nationality 
Republic of China (until 1990) American (since 1990) 
Alma mater 
Chinese University of Hong Kong (B.A. 1969) University of California, Berkeley (Ph. D 1971) 
Known for 
Calabi–Yau manifold Yau's conjecture and many other concepts 
Spouse(s)  Yu Yun 
Children  2 Sons 
Awards 
John J. Carty Award (1981) Veblen Prize (1981) Fields Medal (1982) Crafoord Prize (1994) National Medal of Science (1997) Wolf Prize (2010) 
Scientific career  
Fields  Mathematics 
Institutions 
Harvard University Stanford University Stony Brook University Institute for Advanced Study 
Doctoral advisor  ShiingShen Chern 
Doctoral students 
Richard Schoen (Stanford, 1977) Jun Li (Stanford, 1989) HuaiDong Cao (Princeton, 1986) Gang Tian (Harvard, 1988) Lizhen Ji (Northeastern, 1991) Kefeng Liu (Harvard, 1993) MuTao Wang (Harvard, 1998) ChiuChu Melissa Liu (Harvard, 2002) Mark Stern (Princeton, 1984) 
ShingTung Yau (/jaʊ/; Chinese: 丘成桐; pinyin: Qiū Chéngtóng; Cantonese Yale: Yāu Sìngtùng; born April 4, 1949) is a Hong Kong and naturalized American mathematician. He was awarded the Fields Medal in 1982. He is currently the William Caspar Graustein Professor of Mathematics at Harvard.^{[1]}
Yau's work is mainly in differential geometry, especially in geometric analysis. His contributions have influenced both physics and mathematics, and he has been active at the interface between geometry and theoretical physics. His proof of the positive energy theorem in general relativity demonstrated—sixty years after its discovery—that Einstein's theory is consistent and stable. His proof of the Calabi conjecture allowed physicists to show, using Calabi–Yau compactification, that string theory is a viable candidate for a unified theory of nature. Calabi–Yau manifolds are part of the standard toolkit for string theorists today.
Contents
Biography
Yau was born in Shantou, Guangdong Province, China with Hakka ancestry in Jiaoling, Guangdong to a family of eight children. When he was only a few months old, his family emigrated to Hong Kong, where they lived in Yuen Long and Shatin. Yau's father, Chiou Chenying, was a philosophy professor.
After graduating from Pui Ching Middle School, he studied mathematics at the Chinese University of Hong Kong from 1966 to 1969. Yau left for the University of California, Berkeley in the fall of 1969, where he received his Ph.D. in mathematics two years later, under the supervision of ShiingShen Chern. He spent a year as a member of the Institute for Advanced Study at Princeton before joining Stony Brook University in 1972 as an assistant professor. In 1974, he became an associate professor at Stanford University.^{[2]} Yau has held American citizenship since 1990.^{[3]}^{[4]}
From 1984 to 1987 he worked at UCSD.^{[5]} Since 1987, he has been at Harvard University.^{[6]} He is also involved in the activities of mathematics research institutes in Hong Kong and the Chinese mainland. In addition to his research interests, he is active in educational reform initiatives for primary and secondaryschool mathematics in China, and his criticisms of the Chinese mainland education system, corruption in the academic world in the Chinese mainland, and the quality of mathematical research and education, have been widely publicized.
Contributions to mathematics
Duong Hong Phong of Columbia University has commented on the influence of Yau's research in geometric analysis.^{[7]}
Work on conjectures
Calabi conjecture
Yau's solution of the Calabi conjecture, concerning the existence of an Einstein–Kähler metric, has farreaching consequences. The existence of such a canonical unique metric allows one to give explicit representatives of characteristic classes. Calabi–Yau manifolds are now fundamental in string theory, where the Calabi conjecture provides an essential piece in the model.
In algebraic geometry, the Calabi conjecture implies the Miyaoka–Yau inequality on Chern numbers of surfaces, a characterization of the complex projective plane and quotients of the twodimensional complex unit ball, an important class of Shimura varieties.
Yau also made a contribution in the case that the first Chern number c_{1} > 0, and conjectured its relation to the stability in the sense of geometric invariant theory in algebraic geometry. This has motivated the work of Simon Donaldson on scalar curvature and stability. Another important result of Donaldson–Uhlenbeck–Yau is that a holomorphic vector bundle is stable (in the sense of David Mumford) if and only if there exists an Hermitian–Yang–Mills metric on it. This has many consequences in algebraic geometry, such as the characterization of certain symmetric spaces, Chern number inequalities for stable bundles, and the restriction of the fundamental groups of a Kähler manifold.
Positive mass conjecture and existence of black holes
Yau pioneered the method of using minimal surfaces to study geometry and topology. By analyzing how minimal surfaces behave in spacetime, Yau and Richard Schoen proved the longstanding conjecture that the total mass in general relativity is positive.
This theorem implies that flat spacetime is stable, a fundamental issue for the theory of general relativity. Briefly, the positive mass conjecture says that if a threedimensional manifold has positive scalar curvature and is asymptotically flat, then a constant that appears in the asymptotic expansion of the metric is positive. A continuation of the above work leads to another result in relativity proved by Yau, an existence theorem for black holes. Yau and Schoen continued their work on manifolds with positive scalar curvature, which led to Schoen's final solution of the Yamabe problem.
Smith conjecture
Yau and William H. Meeks resolved the wellknown question of whether the Douglas solution of a minimal disk for an external Jordan curve, the Plateau problem, in three space, is always embedded if the boundary curve is a subset of a convex boundary. They then went on to prove that these embedded minimal surfaces are equivariant for finite group actions. Combining this work with a result by William Thurston, Cameron Gordon assembled a proof of the Smith conjecture: for any cyclic group acting on a sphere, the set of fixed points is not a knotted curve.
Hermitian Yang–Mills connection and stable vector bundles
Yau and Karen Uhlenbeck proved the existence and uniqueness of Hermitian–Einstein metrics (or equivalently Hermitian Yang–Mills connections) for stable bundles on any compact Kähler manifold, extending an earlier result of Donaldson for projective algebraic surfaces, and M. S. Narasimhan and C. S. Seshadri for algebraic curves. Both the results and methods of this paper have been influential in parts of both algebraic geometry and string theory. This result is now usually called the Donaldson–Uhlenbeck–Yau Theorem.
Frankel conjecture
Yau and YumTong Siu proved the 1981 Frankel conjecture in complex geometry, stating that any compact positively curved Kähler manifold is biholomorphic to complex projective space. An independent proof was given by Shigefumi Mori, using methods of algebraic geometry in positive characteristic.
Mirror conjecture
With Bong Lian and Kefeng Liu, Yau proved the mirror formulas conjectured by string theorists. These formulas give the explicit numbers of rational curves of all degrees in a large class of Calabi–Yau manifolds, in terms of the Picard–Fuchs equations of the corresponding mirror manifolds. Givental had earlier sketched a proof of the mirror formulas in a paper on "Equivariant GromovWitten invariants" (Internat. Math. Res. Notices 1996), but his argument contained substantial gaps and wrong arguments. Some of these were fixed and new key ideas were added to give a complete proof in the paper by LianLiuYau.^{[8]}
New methods and concepts
Gradient estimates and Harnack inequalities
Yau developed the method of gradient estimates for Harnack's inequalities. This method has been used and refined by Yau and other mathematicians to attack, for example, bounds on the heat kernel. Early in 1981, Yau suggested to Richard S. Hamilton that he use the Ricci flow to realize naturally the canonical decomposition of a threedimensional manifold into pieces, each of which has a geometric structure, in the Thurston program. Hamilton amplified their results, leading to the Li–Yau–Hamilton inequality for the Ricci flow equations.
Gradient estimates were also used in Yau's joint work with ShiuYuen Cheng to give a complete proof of the higherdimensional Hermann Minkowski problem and the Dirichlet problem for the real Monge–Ampère equation, and other results on the Kähler–Einstein metric of bounded pseudoconvex domains.
Uniformization of complex manifolds
When Yau was a graduate student, he started to generalize the uniformization theorem of Riemann surfaces to higherdimensional complex Kähler manifolds. For a compact manifold with positive bisectional curvature, the Frankel conjecture  proved by Siu and Yau, and independently by Mori  shows that it is complex projective space. Yau proposed a series of conjectures when the manifold is noncompact, and made contributions towards their solutions. For example, when the bisectional curvature is positive, it must be biholomorphic to C^{n}.
Harmonic maps and rigidity
When Yau was working on his thesis about manifolds with nonpositive curvature and their fundamental groups, he realized that it is possible to use harmonic maps to give alternative proofs of some results there. He was aware of the Mostow rigidity theorem for locally symmetric spaces, which he used to prove the uniqueness of complex structure of quotients of complex balls. He proposed that harmonic maps be used to prove rigidity of the complex structure for Kähler manifolds with strongly negative curvature, a program that was successfully carried out by YumTong Siu. This method, the SiuYau method, has been extended to prove strong and superrigidities of many locally symmetric spaces.
Minimal submanifolds
Yau has used minimal submanifolds in his solutions of the Positive Mass Conjecture, the Smith conjecture, and the Frankel conjecture, among others. Many other mathematicians have since applied minimal surfaces to other problems. Mikhail Gromov's introduction of pseudoholomorphic curves in symplectic geometry has also had an important impact on this field.
Open problems
Yau has compiled an influential set of open problems in geometry.
Existence of minimal surfaces
It is known that any closed surface possesses infinitely many closed geodesics. The first problem in the minimal submanifolds section of Yau's list asks whether any closed threemanifold has infinitely many closed smooth immersed minimal surfaces. At the time it was known from Almgren–Pitts minmax theory the existence of at least one minimal surface. Kei Irie, Fernando Codá Marques, and André Neves made recent progress in this problem in the generic case.^{[9]}
Harmonic functions with controlled growth
One of Yau’s problems is about bounded harmonic functions, and harmonic functions on noncompact manifolds of polynomial growth. After proving nonexistence of bounded harmonic functions on manifolds with positive curvatures, he proposed the Dirichlet problem at infinity for bounded harmonic functions on negatively curved manifolds, and then proceeded to harmonic functions of polynomial growth. Dennis Sullivan tells a story about Yau's geometric intuition, and how it led him to reject an analytical proof of Sullivan's. Michael Anderson independently found the same result about bounded harmonic function on simply connected negatively curved manifolds using a geometric convexity construction.^{[7]}
Rank rigidity of nonpositively curved manifolds
Again motivated by Mostow's strong rigidity theorem, Yau called for a notion of rank for general manifolds extending the one for locally symmetric spaces, and asked for rigidity properties for higher rank metrics. Advances in this direction have been made by Ballmann, Brin and Eberlein in their work on nonpositive curved manifolds, Gromov's and Eberlein's metric rigidity theorems for higher rank locally symmetric spaces and the classification of closed higher rank manifolds of nonpositive curvature by Ballmann and BurnsSpatzier. This leaves rank 1 manifolds of nonpositive curvature as the focus of research. They behave more like manifolds of negative curvature, but remain poorly understood in many regards.
Kähler–Einstein metrics and stability of manifolds
It is known that if a complex manifold has a Kähler–Einstein metric, then its tangent bundle is stable. Yau realized early in 1980s that the existence of special metrics on Kähler manifolds is equivalent to the stability of the manifolds. Various people including Simon Donaldson have made progress to understand such a relation.
Mirror symmetry
He has collaborated with string theorists including Strominger, Vafa and Witten, and as postdoctorals from theoretical physics with B. Greene, E. Zaslow and A. Klemm . The Strominger–Yau–Zaslow program is to construct explicitly mirror manifolds. David Gieseker wrote of the seminal role of the Calabi conjecture in relating string theory with algebraic geometry, in particular for the developments of the SYZ program, mirror conjecture and Yau–Zaslow conjecture.^{[7]}
Initiatives in mainland China and Taiwan
Yau was born in China but grew up in Hong Kong. After the door of China was opened to the West in the late 1970s, Yau revisited China in 1979 on the invitation of Hua Luogeng.
To help develop Chinese mathematics, Yau started by educating students from China. He then began establishing mathematics research institutes and centers, organizing conferences at all levels, initiating outreach programs, and raising private funds for these purposes. John Coates has commented on Yau's success as a fundraiser.^{[7]} The first of Yau's initiatives is The Institute of Mathematical Sciences at The Chinese University of Hong Kong in 1993. The goal is to “organize activities related to a broad variety of fields including both pure and Applied mathematics, scientific computation, image processing, mathematical physics and statistics. The emphasis is on interaction and linkages with the physical sciences, engineering, industry and commerce.”
Yau's second major initiative is the Morningside Center of Mathematics in Beijing, established in 1996. Part of the money for the building and regular operations was raised by Yau from the Morningside Foundation in Hong Kong. Yau also proposed organizing the International Congress of Chinese Mathematicians, which is now held every three years. The first congress was held at the Morningside Center from December 12 to 18, 1998.
His third initiative is the Center of Mathematical Sciences at Zhejiang University, established in 2002. Yau is the director of all three mathematics institutes and visits them on a regular basis.
Yau went to Taiwan to attend a conference in 1985. In 1990, he was invited by Liu Chaoshiuan, then the President of National Tsinghua University, to visit the university for a year. A few years later, he convinced Liu, thenchairman of National Science Council, to create the National Center of Theoretical Sciences (NCTS), which was established at Hsinchu in 1998. He was the chairman of the Advisory Board of the NCTS until 2005.
Outreach
His classmate at college Y.C.Siu speaks of Yau as an ambassador of mathematics.^{[7]} In Hong Kong, with the support of Ronnie Chan, Yau set up the Hang Lung Award for high school students. He has also organized and participated in meetings for high school and college students, such as the panel discussions Why Math? Ask Masters! in Hangzhou, July 2004, and The Wonder of Mathematics in Hong Kong, December 2004. Yau organized the JDG conference surveying developments in geometry and related fields, in addition to the annual Current development of mathematics conference. Yau also coinitiated a series of books on popular mathematics, "Mathematics and Mathematical People".
Honors and awards
Yau has received numerous honors and awards,^{[10]} including:
Prizes and awards
 1979, California Scientist of the Year.
 1981, Oswald Veblen Prize in Geometry.
 1981, John J. Carty Award for the Advancement of Science, United States National Academy of Sciences.^{[11]}
 1982, Fields Medal, for "his contributions to partial differential equations, to the Calabi conjecture in algebraic geometry, to the positive mass conjecture of general relativity theory, and to real and complex Monge–Ampère equations."
 1984, Science Digest, America’s 100 Brightest Scientists under 40.
 1991, Humboldt Research Award, Alexander von Humboldt Foundation, Germany.
 1994, Crafoord Prize.^{[12]}
 1997, United States National Medal of Science.
 2003, China International Scientific and Technological Cooperation Award, for “his outstanding contribution to PRC in aspects of making progress in sciences and technology, training researchers.”
 2010, Wolf Prize in Mathematics, for "his work in geometric analysis and mathematical physics".^{[13]}
Research fellowships
 1975–1976, Sloan Fellow.
 1982, Guggenheim Fellowship.
 1984–1985, MacArthur Fellow.
Honorary professorships
 Honorary Professor, Hunan Normal University (appointed on Dec 22, 2009).
 Honorary Professor, Northwest University (appointed on Jul 15, 2009).^{[14]}
 Honorary Professor, North University of China (appointed on Jun 18, 2009).^{[15]}
 Honorary Professor, Huazhong University of Science and Technology (appointed on Jan 15, 2006).^{[16]}
 Honorary Professor, University of Science and Technology of China (appointed in 1999).
 Honorary Professor, Peking University (appointed in 1998).
 Honorary Professor, Zhejiang University (appointed in 1998).
 Honorary Professor, Nankai University (appointed in 1993).
 Honorary Professor, Tsinghua University (appointed in 1987).
 Honorary Professor, Hangzhou University (appointed in 1987).
 Honorary Professor, Fudan University (appointed in 1983).
Honorary degrees
 Honorary Degree of Doctor of Science, The Chinese University of Hong Kong (1980)
 Honorary Master of Arts, Harvard University (1987)
 Honorary Degree of Doctor of Science, National Chiao Tung University, Taiwan (1997)
 Honorary Degree of Doctor of Science, National Tsing Hua University, Taiwan (2000)
 Doctor of Science honoris causa, The University of Macau (2002)^{[17]}
 Honorary Doctorate, Zhejiang University (Mar 25, 2003).^{[18]}
 Honorary Degree of Doctor of Science, National Central University (Jul 9, 2004)^{[19]}
 Doctor of Science honoris causa, The Hong Kong University of Science and Technology (Nov, 2004)^{[20]}
 Doctor of Science, Polytechnic University in Brooklyn, New York (2005)
 Doctor of Science, National Taiwan University (2005)
 Doctor of Science, Lehigh University (2009)
 Doctor of Science, National Cheng Kung University (2010)
 Doctor of Mathematics, University of Waterloo, Canada (Jun 17, 2011)
 Doctor of Humane Letters, University of Illinois at Chicago (May 11, 2014)
Academic memberships
 Foreign Member, Indian National Academy of Science (elected in 2008).
 Foreign Member, National Academy of Lincei of Italy (elected in 2005).
 Foreign Member, Russian Academy of Sciences (elected in 2003).
 Foreign member, Chinese Academy of Sciences (elected in 1995).
 Member, United States National Academy of Science (elected in 1993).
 Academician, Academic Sinica (elected in 1984).
 Member, American Academy of Arts and Sciences (elected in 1982).
 Honorary Member, Academic Committee of the Institute of Mathematics, Chinese Academy of Sciences (elected in 1980).
 Fellow, American Association for the Advancement of Science.
 Fellow, Society for Industrial and Applied Mathematics.
 Fellow, American Physical Society.
 Member, Boston Academy of Arts and Sciences.
 Member, New York Academy of Science.
 Honorary Fellow, Shaw College of The Chinese University of Hong Kong.^{[21]}
 Fellow, American Mathematical Society (elected in 2012)^{[22]}
Poincaré conjecture controversy
In August 2006, a New Yorker article, Manifold Destiny, alleged that Yau was downplaying Grigori Perelman's work on the Poincaré conjecture.^{[23]} Yau claimed that this article was defamatory, and threatened a lawsuit. The New Yorker stood by the story and no lawsuit was filed. In September 2006, Yau established a public relations website, which disputed points in it. Seventeen mathematicians, including two quoted in the New Yorker article, posted letters of strong support.^{[24]}
On October 17, 2006, a more sympathetic profile of Yau appeared in The New York Times.^{[25]} It devoted about half its length to the Perelman affair. The article stated that Yau had alienated some colleagues, but represented Yau's position as that Perelman's proof was not generally understood and he "had a duty to dig out the truth of the proof".^{[26]}
Publications
 Yau, Shing Tung (1978), "On the Ricci curvature of a compact Kähler manifold and the complex MongeAmpère equation. I", Communications on Pure and Applied Mathematics, 31 (3): 339–411, doi:10.1002/cpa.3160310304, MR 0480350
 2010. (with Steve Nadis) The Shape of Inner Space: String Theory and the Geometry of the Universe's Hidden Dimensions. Basic Books. ISBN 9780465020232.
See also
References
 ^ "Questions and answers with ShingTung Yau", Physics Today, 11 April 2016.
 ^ "ShingTung Yau (Biography)".
 ^ Yau received American citizenship in 1990. The People's Republic of China does not recognize dual nationality.

^ Overbye, Dennis (October 17, 2006). "Scientist at Work: ShingTung Yau The Emperor of Math". The New York Times. Retrieved September 14, 2013.
He became a United States citizen in 1990.
 ^ http://ucsdnews.ucsd.edu/archive/newsrel/science/mczelmanov.htm
 ^ "Department of Mathematics faculty, Harvard University".
 ^ ^{a} ^{b} ^{c} ^{d} ^{e} Page at Center of Mathematical Sciences at Zhejiang University
 ^ "On the Mirror Conjecture" (PDF).
 ^ https://arxiv.org/abs/1710.10752
 ^ "YAU, SHINGTUNG" (php). International Center for Scientific Research. Retrieved Jan 1, 2009.
 ^ "John J. Carty Award for the Advancement of Science". United States National Academy of Sciences. Archived from the original on 20101229. Retrieved Jan 1, 2009.
 ^ “...for his development of nonlinear techniques in differential geometry leading to the solution of several outstanding problems.”
 ^ Malkah Fleisher, Winners of Prestigious Wolf Prize Announced
 ^ 丘成桐受聘西北大学名誉教授 (shtml) (in Chinese). Chinese Academy of Sciences. 20090715. Retrieved Jan 1, 2009.
 ^ 著名数学家丘成桐受聘我校荣誉教授 (in Chinese). North University of China. 20090618. Archived from the original (shtml) on 20110707. Retrieved Jan 1, 2009.
 ^ 靖咏安 (20060115). 中科院外籍院士丘成桐受聘我校名誉教授 (in Chinese). Huazhong University of Science and Technology. Archived from the original (shtml) on 20110723. Retrieved Jan 1, 2009.
 ^ "Honorary Degrees and Titles" (pdf) (in Chinese and English). The University of Macau. August 9, 2009. Retrieved January 1, 2009.
 ^ 著名数学家丘成桐获浙江大学名誉博士学位 (in Chinese). Zhejiang University News Agency. 20030325. Archived from the original (php) on 20110721. Retrieved Jan 1, 2009.
 ^ 國立中央大學名譽博士頒授 (in Chinese). National Central University. Archived from the original on 20090701. Retrieved Jan 1, 2004.
 ^ "Distinguished Leaders to be Awarded Honorary Doctorates" (pdf). The Hong Kong University of Science and Technology (HKUST). August 26, 2004. Retrieved Jan 1, 2009.
 ^ "Colleges" (pdf) (in Chinese and English). Information Services Office, The Chinese University of Hong Kong. October 15, 2007. Retrieved January 1, 2009.
 ^ List of Fellows of the American Mathematical Society, retrieved 20130901.
 ^ Manifold Destiny: A legendary problem and the battle over who solved it. Retrieved 8 March 2015.
 ^ Yau's website, with information on his legal action and letter to The New Yorker
 ^ Dennis Overbye (17 October 2006). "Shingtung Yau: The Emperor of Math". New York Times.
 ^ Famous scientist slams academic corruption in China, China View (Xinhua), 17 August 2006. Retrieved on 20080805.
External links
 Discover Magazine Interview, June 2010 issue
 Interview (11 pages long in Traditional Chinese)
 Yau's autobiographical account (mostly English, some Chinese)
 O'Connor, John J.; Robertson, Edmund F., "ShingTung Yau", MacTutor History of Mathematics archive, University of St Andrews.
 ShingTung Yau at the Mathematics Genealogy Project
 Banquet photos
 Yau's website, with information on his legal action and letter to The New Yorker
 Yau's Public Relations agent, Spector and Associates
 Richard S Hamilton' Letter to Yau ShingTung' Attorney on September 25, 2006
 Plugging A Math Gap
 UC Irvine courting Yau with a $2.5 million professorship
 International Conference Celebrating Shing Tung Yau's Birthday 8/27/20089/1/2008 Harvard University
 1949 births
 20thcentury American mathematicians
 21stcentury mathematicians
 Alumni of the Chinese University of Hong Kong
 Chinese emigrants to the United States
 Differential geometers
 Fellows of the American Mathematical Society
 Fields Medalists
 Foreign Members of the Russian Academy of Sciences
 Foreign Members of the Chinese Academy of Sciences
 Guggenheim Fellows
 Hakka people
 Hong Kong people of Hakka descent
 American people of Hakka descent
 People from Jiaoling
 Harvard University faculty
 ISI highly cited researchers
 Institute for Advanced Study faculty
 Living people
 MacArthur Fellows
 Members of Academia Sinica
 Members of the United States National Academy of Sciences
 National Academy of Sciences laureates
 National Medal of Science laureates
 Stanford University faculty
 University of California, Berkeley alumni
 University of California, San Diego faculty
 Zhejiang University faculty
 Alexander von Humboldt Fellows
 Members of Committee of 100
 Chinese mathematicians
 Hakka scientists
 American academics of Chinese descent
 People from Shantou
 Scientists from Guangdong
 Educators from Guangdong