name | Sir Michael Atiyah |
---|---|
birth date | April 22, 1929 |
birth place | Hampstead, London, England |
nationality | United Kingdom |
field | Mathematics |
work institutions | University of CambridgeUniversity of OxfordInstitute for Advanced StudyUniversity of LeicesterUniversity of Edinburgh |
alma mater | Victoria College, AlexandriaManchester Grammar SchoolTrinity College, Cambridge |
doctoral advisor | W. V. D. Hodge |
doctoral students | Simon DonaldsonK. David ElworthyNigel HitchinFrances KirwanPeter KronheimerRuth LawrenceGeorge LusztigJack MoravaIan R. PorteousBrian SandersonGraeme SegalDavid O. Tall |
awards | Fields Medal (1966)Copley Medal (1988)Abel Prize (2004) |
footnotes | }} |
Atiyah grew up in Sudan and Egypt but spent most of his academic life in the United Kingdom at Oxford and Cambridge, and in the United States at the Institute for Advanced Study. He has been president of the Royal Society (1990–1995), master of Trinity College, Cambridge (1990–1997), chancellor of the University of Leicester (1995–2005), and president of the Royal Society of Edinburgh (2005–2008). He is currently retired, and is an honorary professor at the University of Edinburgh.
Atiyah's mathematical collaborators include Raoul Bott, Friedrich Hirzebruch and Isadore Singer, and his students include Graeme Segal, Nigel Hitchin and Simon Donaldson. Together with Hirzebruch, he laid the foundations for topological K-theory, an important tool in algebraic topology, which, informally speaking, describes ways in which spaces can be twisted. His best known result, the Atiyah–Singer index theorem, was proved with Singer in 1963 and is widely used in counting the number of independent solutions to differential equations. Some of his more recent work was inspired by theoretical physics, in particular instantons and monopoles, which are responsible for some subtle corrections in quantum field theory. He was awarded the Fields Medal in 1966, the Copley Medal in 1988, and the Abel Prize in 2004.
Atiyah married Lily Brown on 30 July 1955, with whom he has three sons. He spent the academic year 1955–1956 at the Institute for Advanced Study, Princeton, then returned to Cambridge University, where he was a research fellow and assistant lecturer (1957–1958), then a university lecturer and tutorial fellow at Pembroke College (1958–1961). In 1961, he moved to the University of Oxford, where he was a reader and professorial fellow at St Catherine's College (1961–1963). He became Savilian Professor of Geometry and a professorial fellow of New College, Oxford from 1963 to 1969. He then took up a three year professorship at the Institute for Advanced Study in Princeton after which he returned to Oxford as a Royal Society Research Professor and professorial fellow of St Catherine's College. He was president of the London Mathematical Society from 1974 to 1976.
Atiyah has been active on the international scene, for instance as president of the Pugwash Conferences on Science and World Affairs from 1997 to 2002. He also contributed to the foundation of the InterAcademy Panel on International Issues, the Association of European Academies (ALLEA), and the European Mathematical Society (EMS).
Within the United Kingdom, he was involved in the creation of the Isaac Newton Institute for Mathematical Sciences in Cambridge and was its first director (1990–1996). He was President of the Royal Society (1990–1995), Master of Trinity College, Cambridge (1990–1997), Chancellor of the University of Leicester (1995–2005), and president of the Royal Society of Edinburgh (2005–2008). He is now retired and is an honorary professor at the University of Edinburgh.
His later research on gauge field theories, particularly Yang–Mills theory, stimulated important interactions between geometry and physics, most notably in the work of Edward Witten.
Atiyah's many students include Peter Braam 1987, Simon Donaldson 1983, K. David Elworthy 1967, Howard Fegan 1977, Eric Grunwald 1977, Nigel Hitchin 1972, Lisa Jeffrey 1991, Frances Kirwan 1984, Peter Kronheimer 1986, Ruth Lawrence 1989, George Lusztig 1971, Jack Morava 1968, Michael Murray 1983, Peter Newstead 1966, Ian R. Porteous 1961, John Roe 1985, Brian Sanderson 1963, Rolph Schwarzenberger 1960, Graeme Segal 1967, David Tall 1966, and Graham White 1982.
Other contemporary mathematicians who influenced Atiyah include Roger Penrose, Lars Hörmander, Alain Connes and Jean-Michel Bismut. Atiyah said that the mathematician he most admired was Hermann Weyl, and that his favorite mathematicians from before the 20th century were Bernhard Riemann and William Rowan Hamilton.
As an undergraduate Atiyah was interested in classical projective geometry, and wrote his first paper: a short note on twisted cubics. He started research under W. V. D. Hodge and won the Smith's prize for 1954 for a sheaf-theoretic approach to ruled surfaces, which encouraged Atiyah to continue in mathematics, rather than switch to his other interests—architecture and archaeology. His PhD thesis with Hodge was on a sheaf-theoretic approach to Solomon Lefschetz's theory of integrals of the second kind on algebraic varieties, and resulted in an invitation to visit the Institute for Advanced Study in Princeton for a year. While in Princeton he classified vector bundles on an elliptic curve (extending Grothendieck's classification of vector bundles on a genus 0 curve), by showing that any vector bundle is a sum of (essentially unique) indecomposable vector bundles, and then showing that the space of indecomposable vector bundles of given degree and positive dimension can be identified with the elliptic curve. He also studied double points on surfaces, giving the first example of a flop, a special birational transformation of 3-folds that was later heavily used in Mori's work on minimal models for 3-folds. Atiyah's flop can also be used to show that the universal marked family of K3 surfaces is non-Hausdorff.
The simplest example of a vector bundle is the Möbius band (pictured on the right): a strip of paper with a twist in it, which represents a rank 1 vector bundle over a circle (the circle in question being the centerline of the Möbius band). K-theory is a tool for working with higher dimensional analogues of this example, or in other words for describing higher dimensional twistings: elements of the K-group of a space are represented by vector bundles over it, so the Möbius band represents an element of the K-group of a circle.
Topological K-theory was discovered by Atiyah and Friedrich Hirzebruch who were inspired by Grothendieck's proof of the Grothendieck–Riemann–Roch theorem and Bott's work on the periodicity theorem. This paper only discussed the zeroth K-group; they shortly after extended it to K-groups of all degrees, giving the first (nontrivial) example of a generalized cohomology theory.
Several results showed that the newly introduced K-theory was in some ways more powerful than ordinary cohomology theory. Atiyah and Todd used K-theory to improve the lower bounds found using ordinary cohomology by Borel and Serre for the James number, describing when a map from a complex Stiefel manifold to a sphere has a cross section. (Adams and Grant-Walker later showed that the bound found by Atiyah and Todd was best possible.) Atiyah and Hirzebruch used K-theory to explain some relations between Steenrod operations and Todd classes that Hirzebruch had noticed a few years before. The original solution of the Hopf invariant one problem operations by J. F. Adams was very long and complicated, using secondary cohomology operations. Atiyah showed how primary operations in K-theory could be used to give a short solution taking only a few lines, and in joint work with Adams also proved analogues of the result at odd primes.
The Atiyah–Hirzebruch spectral sequence relates the ordinary cohomology of a space to its generalized cohomology theory. (Atiyah and Hirzebruch used the case of K-theory, but their method works for all cohomology theories).
Atiyah showed that for a finite group ''G'', the K-theory of its classifying space, ''BG'', is isomorphic to the completion of its character ring: : The same year they proved the result for ''G'' any compact connected Lie group. Although soon the result could be extended to ''all'' compact Lie groups by incorporating results from Graeme Segal's thesis, that extension was complicated. However a simpler and more general proof was produced by introducing equivariant K-theory, ''i.e.'' equivalence classes of ''G''-vector bundles over a compact ''G''-space ''X''. It was shown that under suitable conditions the completion of the equivariant K-theory of ''X'' is isomorphic to the ordinary K-theory of a space, , which fibred over ''BG'' with fibre ''X'': :
The original result then followed as a corollary by taking ''X'' to be a point: the left hand side reduced to the completion of ''R(G)'' and the right to ''K(BG)''. See Atiyah–Segal completion theorem for more details.
He defined new generalized homology and cohomology theories called bordism and cobordism, and pointed out that many of the deep results on cobordism of manifolds found by R. Thom, C. T. C. Wall, and others could be naturally reinterpreted as statements about these cohomology theories. Some of these cohomology theories, in particular complex cobordism, turned out to be some of the most powerful cohomology theories known.
He introduced the J-group ''J''(''X'') of a finite complex ''X'', defined as the group of stable fiber homotopy equivalence classes of sphere bundles; this was later studied in detail by J. F. Adams in a series of papers, leading to the Adams conjecture.
With Hirzebruch he extended the Grothendieck–Riemann–Roch theorem to complex analytic embeddings, and in a related paper they showed that the Hodge conjecture for integral cohomology is false. The Hodge conjecture for rational cohomology is, as of 2008, a major unsolved problem.
The Bott periodicity theorem was a central theme in Atiyah's work on K-theory, and he repeatedly returned to it, reworking the proof several times to understand it better. With Bott he worked out an elementary proof, and gave another version of it in his book. With Bott and Shapiro he analysed the relation of Bott periodicity to the periodicity of Clifford algebras; although this paper did not have a proof of the periodicity theorem, a proof along similar lines was shortly afterwards found by R. Wood. In he found a proof of several generalizations using elliptic operators; this new proof used an idea that he used to give a particularly short and easy proof of Bott's original periodicity theorem.
The index of a differential operator is closely related to the number of independent solutions (more precisely, it is the differences of the numbers of independent solutions of the differential operator and its adjoint). There are many hard and fundamental problems in mathematics that can easily be reduced to the problem of finding the number of independent solutions of some differential operator, so if one has some means of finding the index of a differential operator these problems can often be solved. This is what the Atiyah–Singer index theorem does: it gives a formula for the index of certain differential operators, in terms of topological invariants that look quite complicated but are in practice usually straightforward to calculate.
Several deep theorems, such as the Hirzebruch–Riemann–Roch theorem, are special cases of the Atiyah–Singer index theorem. In fact the index theorem gave a more powerful result, because its proof applied to all compact complex manifolds, while Hirzebruch's proof only worked for projective manifolds. There were also many new applications: a typical one is calculating the dimensions of the moduli spaces of instantons. The index theorem can also be run "in reverse": the index is obviously an integer, so the formula for it must also give an integer, which sometimes gives subtle integrality conditions on invariants of manifolds. A typical example of this is Rochlin's theorem, which follows from the index theorem.
The index problem for elliptic differential operators was posed in 1959 by Gel'fand. He noticed the homotopy invariance of the index, and asked for a formula for it by means of topological invariants. Some of the motivating examples included the Riemann–Roch theorem and its generalization the Hirzebruch–Riemann–Roch theorem, and the Hirzebruch signature theorem. Hirzebruch and Borel had proved the integrality of the  genus of a spin manifold, and Atiyah suggested that this integrality could be explained if it were the index of the Dirac operator (which was rediscovered by Atiyah and Singer in 1961).
The first announcement of the Atiyah–Singer theorem was their 1963 paper. The proof sketched in this announcement was inspired by Hirzebruch's proof of the Hirzebruch–Riemann–Roch theorem and was never published by them, though it is described in the book by Palais. Their first published proof was more similar to Grothendieck's proof of the Grothendieck–Riemann–Roch theorem, replacing the cobordism theory of the first proof with K-theory, and they used this approach to give proofs of various generalizations in a sequence of papers from 1968 to 1971.
Instead of just one elliptic operator, one can consider a family of elliptic operators parameterized by some space ''Y''. In this case the index is an element of the K-theory of ''Y'', rather than an integer. If the operators in the family are real, then the index lies in the real K-theory of ''Y''. This gives a little extra information, as the map from the real K theory of ''Y'' to the complex K theory is not always injective.
With Bott, Atiyah found an analogue of the Lefschetz fixed-point formula for elliptic operators, giving the Lefschetz number of an endomorphism of an elliptic complex in terms of a sum over the fixed points of the endomorphism. As special cases their formula included the Weyl character formula, and several new results about elliptic curves with complex multiplication, some of which were initially disbelieved by experts. Atiyah and Segal combined this fixed point theorem with the index theorem as follows. If there is a compact group action of a group ''G'' on the compact manifold ''X'', commuting with the elliptic operator, then one can replace ordinary K theory in the index theorem with equivariant K-theory. For trivial groups ''G'' this gives the index theorem, and for a finite group ''G'' acting with isolated fixed points it gives the Atiyah–Bott fixed point theorem. In general it gives the index as a sum over fixed point submanifolds of the group ''G''.
Atiyah solved a problem asked independently by Hörmander and Gel'fand, about whether complex powers of analytic functions define distributions. Atiyah used Hironaka's resolution of singularities to answer this affirmatively. An ingenious and elementary solution was found at about the same time by J. Bernstein, and discussed by Atiyah.
As an application of the equivariant index theorem, Atiyah and Hirzeburch showed that manifolds with effective circle actions have vanishing Â-genus. (Lichnerowicz showed that if a manifold has a metric of positive scalar curvature then the Â-genus vanishes.)
With Elmer Rees, Atiyah studied the problem of the relation between topological and holomorphic vector bundles on projective space. They solved the simplest unknown case, by showing that all rank 2 vector bundles over projective 3-space have a holomorphic structure. Horrocks had previously found some non-trivial examples of such vector bundles, which were later used by Atiyah in his study of instantons on the 4-sphere.
Atiyah, Bott and Vijay K. Patodi gave a new proof of the index theorem using the heat equation.
If the manifold is allowed to have boundary, then some restrictions must be put on the domain of the elliptic operator in order to ensure a finite index. These conditions can be local (like demanding that the sections in the domain vanish at the boundary) or more complicated global conditions (like requiring that the sections in the domain solve some differential equation). The local case was worked out by Atiyah and Bott, but they showed that many interesting operators (e.g., the signature operator) do not admit local boundary conditions. To handle these operators, Atiyah, Patodi and Singer introduced global boundary conditions equivalent to attaching a cylinder to the manifold along the boundary and then restricting the domain to those sections that are square integrable along the cylinder. This resulted in a series of papers on spectral asymmetry, which were later unexpectedly used in theoretical physics, in particular in Witten's work on anomalies.
The fundamental solutions of linear hyperbolic partial differential equations often have Petrovsky lacunas: regions where they vanish identically. These were studied in 1945 by I. G. Petrovsky, who found topological conditions describing which regions were lacunas. In collaboration with Bott and Lars Gårding, Atiyah wrote three papers updating and generalizing Petrovsky's work.
Atiyah showed how to extend the index theorem to some non-compact manifolds, acted on by a discrete group with compact quotient. The kernel of the elliptic operator is in general infinite dimensional in this case, but it is possible to get a finite index using the dimension of a module over a von Neumann algebra; this index is in general real rather than integer valued. This version is called the ''L2 index theorem,'' and was used by Atiyah and Schmid to give a geometric construction, using square integrable harmonic spinors, of Harish-Chandra's discrete series representations of semisimple Lie groups. In the course of this work they found a more elementary proof of Harish-Chandra's fundamental theorem on the local integrability of characters of Lie groups.
With H. Donnelly and I. Singer, he extended Hirzebruch's formula (relating the signature defect at cusps of Hilbert modular surfaces to values of L-functions) from real quadratic fields to all totally real fields.
In a series of papers with several authors, Atiyah classified all instantons on 4 dimensional Euclidean space. It is more convenient to classify instantons on a sphere as this is compact, and this is essentially equivalent to classifing instantons on Euclidean space as this is conformally equivalent to a sphere and the equations for instantons are conformally invariant. With Hitchin and Singer he calculated the dimension of the moduli space of irreducible self-dual connections (instantons) for any principle bundle over a compact 4-dimensional Riemannian manifold. For example, the dimension of the space of SU2 instantons of rank ''k''>0 is 8''k''−3. To do this they used the Atiyah–Singer index theorem to calculate the dimension of the tangent space of the moduli space at a point; the tangent space is essentially the space of solutions of an elliptic differential operator, given by the linearization of the non-linear Yang–Mills equations. These moduli spaces were later used by Donaldson to construct his invariants of 4-manifolds. Atiyah and Ward used the Penrose correspondence to reduce the classification of all instantons on the 4-sphere to a problem in algebraic geometry. With Hitchin he used ideas of Horrocks to solve this problem, giving the ADHM construction of all instantons on a sphere; Manin and Drinfeld found the same construction at the same time, leading to a joint paper by all four authors. Atiyah reformulated this construction using quaternions and wrote up a leisurely account of this classification of instantons on Euclidean space as a book.
Atiyah's work on instanton moduli spaces was used in Donaldson's work on Donaldson theory. Donaldson showed that the moduli space of (degree 1) instantons over a compact simply connected 4-manifold with positive definite intersection form can be compactified to give a cobordism between the manifold and a sum of copies of complex projective space. He deduced from this that the intersection form must be a sum of one dimensional ones, which led to several spectacular applications to smooth 4-manifolds, such as the existence of non-equivalent smooth structures on 4 dimensional Euclidean space. Donaldson went on to use the other moduli spaces studied by Atiyah to define Donaldson invariants, which revolutionized the study of smooth 4-manifolds, and showed that they were more subtle than smooth manifolds in any other dimension, and also quite different from topological 4-manifolds. Atiyah described some of these results in a survey talk.
Green's functions for linear partial differential equations can often be found by using the Fourier transform to convert this into an algebraic problem. Atiyah used a non-linear version of this idea. He used the Penrose transform to convert the Green's function for the conformally invariant Laplacian into a complex analytic object, which turned out to be essentially the diagonal embedding of the Penrose twistor space into its square. This allowed him to find an explicit formula for the conformally invariant Green's function on a 4-manifold.
In his paper with Jones, he studied the topology of the moduli space of SU(2) instantons over a 4-sphere. They showed that the natural map from this moduli space to the space of all connections induces epimorphisms of homology groups in a certain range of dimensions, and suggested that it might induce isomorphisms of homology groups in the same range of dimensions. This became known as the Atiyah–Jones conjecture, and was later proved by several mathematicians.
Harder and M. S. Narasimhan described the cohomology of the moduli spaces of stable vector bundles over Riemann surfaces by counting the number of points of the moduli spaces over finite fields, and then using the Weil conjectures to recover the cohomology over the complex numbers. Atiyah and R. Bott used Morse theory and the Yang–Mills equations over a Riemann surface to reproduce and extending the results of Harder and Narasimhan.
An old result due to Schur and Horn states that the set of possible diagonal vectors of an Hermitian matrix with given eigenvalues is the convex hull of all the permutations of the eigenvalues. Atiyah proved a generalization of this that applies to all compact symplectic manifolds acted on by a torus, showing that the image of the manifold under the moment map is a convex polyhedron, and with Pressley gave a related generalization to infinite dimensional loop groups.
Duistermaat and Heckman found a striking formula, saying that the push-forward of the Liouville measure of a moment map for a torus action is given exactly by the stationary phase approximation (which is in general just an asymptotic expansion rather than exact). Atiyah and Bott showed that this could be deduced from a more general formula in equivariant cohomology, which was a consequence of well-known localization theorems. Atiyah showed that the moment map was closely related to geometric invariant theory, and this idea was later developed much further by his student F. Kirwan. Witten shortly after applied the Duistermaat–Heckman formula to loop spaces and showed that this formally gave the Atiyah–Singer index theorem for the Dirac operator; this idea was lectured on by Atiyah.
With Hitchin he worked on magnetic monopoles, and studied their scattering using an idea of Nick Manton. His book with Hitchin gives a detailed description of their work on magnetic monopoles. The main theme of the book is a study of a moduli space of magnetic monopoles; this has a natural Riemannian metric, and a key point is that this metric is complete and hyperkahler. The metric is then used to study the scattering of two monopoles, using a suggestion of N. Manton that the geodesic flow on the moduli space is the low energy approximation to the scattering. For example, they show that a head-on collision between two monopoles results in 90-degree scattering, with the direction of scattering depending on the relative phases of the two monopoles. He also studied monopoles on hyperbolic space.
Atiyah showed that instantons in 4 dimensions can be identified with instantons in 2 dimensions, which are much easier to handle. There is of course a catch: in going from 4 to 2 dimensions the structure group of the gauge theory changes from a finite dimensional group to an infinite dimensional loop group. This gives another example where the moduli spaces of solutions of two apparently unrelated nonlinear partial differential equations turn out to be essentially the same.
Atiyah and Singer found that anomalies in quantum field theory could be interpreted in terms of index theory of the Dirac operator; this idea later became widely used by physicists.
One paper is a detailed study of the Dedekind eta function from the point of view of topology and the index theorem.
Several of his papers from around this time study the connections between quantum field theory, knots, and Donaldson theory. He introduced the concept of a topological quantum field theory, inspired by Witten's work and Segal's definition of a conformal field theory. His book describes the new knot invariants found by Vaughan Jones and Edward Witten in terms of topological quantum field theories, and his paper with L. Jeffrey explains Witten's Lagrangian giving the Donaldson invariants.
He studied skyrmions with Nick Manton, finding a relation with magnetic monopoles and instantons, and giving a conjecture for the structure of the moduli space of two skyrmions as a certain subquotient of complex projective 3-space.
Several papers were inspired by a question of M. Berry, who asked if there is a map from the configuration space of ''n'' points in 3-space to the flag manifold of the unitary group. Atiyah gave an affirmative answer to this question, but felt his solution was too computational and studied a conjecture that would give a more natural solution. He also related the question to Nahm's equation.
With Juan Maldacena and Cumrun Vafa, and E. Witten he described the dynamics of M-theory on manifolds with G2 holonomy. These papers seem to be the first time that Atiyah has worked on exceptional Lie groups.
In his papers with M. Hopkins and G. Segal he returned to his earlier interest of K-theory, describing some twisted forms of K-theory with applications in theoretical physics.
He was elected a foreign member of the National Academy of Sciences, the American Academy of Arts and Sciences (1969), the Academie des Sciences, the Akademie Leopoldina, the Royal Swedish Academy, the Royal Irish Academy, the Royal Society of Edinburgh, the American Philosophical Society, the Indian National Science Academy, the Chinese Academy of Science, the Australian Academy of Science, the Russian Academy of Science, the Ukrainian Academy of Science, the Georgian Academy of Science, the Venezuela Academy of Science, the Norwegian Academy of Science and Letters, the Royal Spanish Academy of Science, the Accademia dei Lincei and the Moscow Mathematical Society.
Atiyah has been awarded honorary degrees by the universities of Bonn, Warwick, Durham, St. Andrews, Dublin, Chicago, Cambridge, Edinburgh, Essex, London, Sussex, Ghent, Reading, Helsinki, Salamanca, Montreal, Wales, Lebanon, Queen's (Canada), Keele, Birmingham, UMIST, Brown, Heriot–Watt, Mexico, Oxford, Hong Kong (Chinese University), The Open University, American University of Beirut, the Technical University of Catalonia and Leicester.
Atiyah was made a Knight Bachelor in 1983 and made a member of the Order of Merit in 1992.
The Michael Atiyah building at the University of Leicester and the Michael Atiyah Chair in Mathematical Sciences at the American University of Beirut were named after him.
Category:1929 births Category:Living people Category:Abel Prize laureates Category:Alumni of Trinity College, Cambridge Category:British mathematicians Category:Fellows of the American Academy of Arts and Sciences Category:Fellows of the Royal Society Category:Fellows of the Royal Society of Edinburgh Category:Fields Medalists Category:Honorary Fellows of Darwin College, Cambridge Category:Knights Bachelor Category:Masters of Trinity College, Cambridge Category:Members of the French Academy of Sciences Category:Members of the Order of Merit Category:Norwegian Academy of Science and Letters Category:Old Mancunians Category:People associated with the University of Leicester Category:People from Hampstead Category:Presidents of the Royal Society Category:Recipients of the Copley Medal Category:Royal Medal winners Category:Savilian Professors of Geometry Category:Topologists Category:Fellows of New College, Oxford
ar:مايكل عطية bn:মাইকেল ফ্রান্সিস আটিয়া zh-min-nan:Michael Atiyah cs:Michael Atiyah da:Michael Atiyah de:Michael Francis Atiyah es:Michael Atiyah fr:Michael Atiyah ko:마이클 아티야 it:Michael Atiyah he:מייקל עטיה ht:Michael Atiyah hu:Michael Francis Atiyah nl:Michael Atiyah ja:マイケル・アティヤ no:Michael Francis Atiyah pnb:مائیکل آتیاہ pl:Michael Atiyah pt:Michael Atiyah ro:Michael Atiyah ru:Атья, Майкл Фрэнсис sk:Michael Atiyah sl:Michael Francis Atiyah fi:Michael Atiyah sv:Michael Francis Atiyah uk:Майкл Атія vi:Michael Atiyah zh:迈克尔·阿蒂亚This text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
Name | William Thurston |
---|---|
Birth date | October 30, 1946 |
Nationality | American |
Field | Mathematics |
Work institutions | Cornell UniversityUniversity of California, DavisUniversity of California, BerkeleyPrinceton University |
Alma mater | New College of FloridaUniversity of California, Berkeley |
Doctoral advisor | Morris Hirsch |
Doctoral students | Richard CanaryBenson FarbDavid GabaiWilliam GoldmanSteven KerckhoffYair Minsky |
Prizes | Fields Medal (1982)Oswald Veblen Prize in Geometry (1976)National Academy of Sciences (1983) }} |
In fact, Thurston resolved so many outstanding problems in foliation theory in such a short period of time that, according to Thurston, it led to a kind of exodus from the field, where advisors counselled students against going into foliation theory because Thurston was "cleaning out the subject" (see "On Proof and Progress in Mathematics", especially section 6 ).
Inspired by their work, Thurston took a different, more explicit means of exhibiting the hyperbolic structure of the figure eight knot complement. He showed that the figure eight knot complement could be decomposed as the union of two regular ideal hyperbolic tetrahedra whose hyperbolic structures matched up correctly and gave the hyperbolic structure on the figure eight knot complement. By utilizing Haken's normal surface techniques, he classified the incompressible surfaces in the knot complement. Together with his analysis of deformations of hyperbolic structures, he concluded that all but 10 Dehn surgeries on the figure eight knot resulted in irreducible, non-Haken non-Seifert-fibered 3-manifolds. These were the first such examples; previously it had been believed that except for certain Seifert fiber spaces, all irreducible 3-manifolds were Haken. These examples were actually hyperbolic and motivated his next revolutionary theorem.
Thurston proved that in fact most Dehn fillings on a cusped hyperbolic 3-manifold resulted in hyperbolic 3-manifolds. This is his celebrated hyperbolic Dehn surgery theorem.
To complete the picture, Thurston proved a hyperbolization theorem for Haken manifolds. A particularly important corollary is that many knots and links are in fact hyperbolic. Together with his hyperbolic Dehn surgery theorem, this showed that closed hyperbolic 3-manifolds existed in great abundance.
The geometrization theorem has been called ''Thurston's Monster Theorem,'' due to the length and difficulty of the proof. Complete proofs were not written up until almost 20 years later. The proof involves a number of deep and original insights which have linked many apparently disparate fields to 3-manifolds.
Thurston was next led to formulate his geometrization conjecture. This gave a conjectural picture of 3-manifolds which indicated that all 3-manifolds admitted a certain kind of geometric decomposition involving eight geometries, now called Thurston model geometries. Hyperbolic geometry is the most prevalent geometry in this picture and also the most complicated. A proof to that conjecture follows from the recent work of Grigori Perelman (2002–2003).
After completing his Ph.D., he spent a year at the Institute for Advanced Study, then another year at MIT as Assistant Professor. In 1974, he was appointed Professor of Mathematics at Princeton University. In 1991, he returned to UC-Berkeley as Professor of Mathematics and in 1993 became Director of the Mathematical Sciences Research Institute. In 1996, he moved to University of California, Davis. In 2003, he moved again to become Professor of Mathematics at Cornell University.
His Ph.D. students include Richard Canary, Renaud Dreyer, David Gabai, William Goldman, Benson Farb, Detlef Hardorp, Craig Hodgson, Richard Kenyon, Steven Kerckhoff, Robert Meyerhoff, Yair Minsky, Lee Mosher, Igor Rivin, Oded Schramm, Richard Schwartz, Martin Bridgeman, William Floyd and Jeffrey Weeks. His son, Dylan Thurston, is an assistant professor of mathematics at Barnard College, Columbia University.
Thurston has turned his attention in recent years to mathematical education and bringing mathematics to the general public. He has served as mathematics editor for Quantum Magazine, a youth science magazine, and as head of The Geometry Center. As director of Mathematical Sciences Research Institute from 1992 to 1997, he initiated a number of programs designed to increase awareness of mathematics among the public.
In 2005 Thurston won the first AMS Book Prize, for ''Three-dimensional Geometry and Topology''. The prize ''recognizes an outstanding research book that makes a seminal contribution to the research literature''.
Thurston has an Erdős number of 2.
Category:Topologists Category:Members of the United States National Academy of Sciences Category:American mathematicians Category:Fields Medalists Category:University of California, Berkeley faculty Category:Cornell University faculty Category:University of California, Davis Category:New College of Florida alumni Category:1946 births Category:Living people Category:Sloan Research Fellowships Category:University of California, Berkeley alumni
zh-min-nan:William Thurston de:William Thurston es:William Thurston fr:William Thurston ko:윌리엄 서스턴 it:William Thurston ht:William Thurston nl:William Thurston ja:ウィリアム・サーストン no:William Thurston pnb:ولیم تھرسٹن pl:William Thurston pt:William Thurston ru:Тёрстон, Уильям Пол sk:William Thurston sl:William Thurston fi:William Thurston uk:Вільям Терстон zh:威廉·瑟斯顿This text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
Name | Stephen Hawking |
---|---|
Birth name | Stephen William Hawking |
Birth date | January 08, 1942 |
Birth place | Oxford, England, United Kingdom |
Residence | United Kingdom |
Nationality | British |
Fields | Applied mathematicsTheoretical physicsCosmology |
Workplaces | Cambridge UniversityCalifornia Institute of TechnologyPerimeter Institute for Theoretical Physics |
Alma mater | Oxford UniversityCambridge University |
Doctoral advisor | Dennis Sciama |
Academic advisors | Robert Berman |
Doctoral students | Bruce AllenRaphael BoussoFay DowkerMalcolm PerryBernard CarrGary GibbonsHarvey ReallDon PageTim PrestidgeRaymond LaflammeJulian Luttrell |
Known for | Black holesTheoretical cosmologyQuantum gravityHawking radiation |
Influences | Dikran TahtaAlbert Einstein |
Awards | |
Spouse | Jane Hawking(m. 1965–1991, divorced)Elaine Mason(m. 1995–2006, divorced) |
Signature | Hawkingsig.svg }} |
Stephen William Hawking, CH, CBE, FRS, FRSA (born 8 January 1942) is a British theoretical physicist and cosmologist, whose scientific books and public appearances have made him an academic celebrity. He is an Honorary Fellow of the Royal Society of Arts, a lifetime member of the Pontifical Academy of Sciences, and in 2009 was awarded the Presidential Medal of Freedom, the highest civilian award in the United States.
Hawking was the Lucasian Professor of Mathematics at the University of Cambridge for 30 years, taking up the post in 1979 and retiring on 1 October 2009. He is now Director of Research at the Centre for Theoretical Cosmology in the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge. He is also a Fellow of Gonville and Caius College, Cambridge and a Distinguished Research Chair at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario. He is known for his contributions to the fields of cosmology and quantum gravity, especially in the context of black holes. He has also achieved success with works of popular science in which he discusses his own theories and cosmology in general; these include the runaway best seller ''A Brief History of Time'', which stayed on the British ''Sunday Times'' best-sellers list for a record-breaking 237 weeks.
Hawking's key scientific works to date have included providing, with Roger Penrose, theorems regarding gravitational singularities in the framework of general relativity, and the theoretical prediction that black holes should emit radiation, which is today known as Hawking radiation (or sometimes as Bekenstein–Hawking radiation).
Hawking has a motor neurone disease that is related to amyotrophic lateral sclerosis, a condition that has progressed over the years and has left him almost completely paralysed.
After Hawking was born, the family moved back to London, where his father headed the division of parasitology at the National Institute for Medical Research. In 1950, Hawking and his family moved to St Albans, Hertfordshire, where he attended St Albans High School for Girls from 1950 to 1953. (At that time, boys could attend the Girls' school until the age of ten.) From the age of eleven, he attended St Albans School, where he was a good, but not exceptional, student. When asked later to name a teacher who had inspired him, Hawking named his mathematics teacher Dikran Tahta. He maintains his connection with the school, giving his name to one of the four houses and to an extracurricular science lecture series. He has visited it to deliver one of the lectures and has also granted a lengthy interview to pupils working on the school magazine, ''The Albanian''.
Hawking was always interested in science. Inspired by his mathematics teacher, he originally wanted to study the subject at university. However, Hawking's father wanted him to apply to University College, Oxford, where his father had attended. As University College did not have a mathematics fellow at that time, it would not accept applications from students who wished to read that discipline. Hawking therefore applied to read natural sciences, in which he gained a scholarship. Once at University College, Hawking specialised in physics. His interests during this time were in thermodynamics, relativity, and quantum mechanics. His physics tutor, Robert Berman, later said in ''The New York Times Magazine'':
Hawking was passing, but his unimpressive study habits resulted in a final examination score on the borderline between first and second class honours, making an "oral examination" necessary. Berman said of the oral examination:
After receiving his B.A. degree at Oxford in 1962, he stayed to study astronomy. He decided to leave when he found that studying sunspots, which was all the observatory was equipped for, did not appeal to him and that he was more interested in theory than in observation. He left Oxford for Trinity Hall, Cambridge, where he engaged in the study of theoretical astronomy and cosmology.
Hawking was elected as one of the youngest Fellows of the Royal Society in 1974, was created a Commander of the Order of the British Empire in 1982, and became a Companion of Honour in 1989. Hawking is a member of the Board of Sponsors of the ''Bulletin of the Atomic Scientists''.
In 1974, he accepted the Sherman Fairchild Distinguished Scholar visiting professorship at the California Institute of Technology (Caltech) to work with his friend, Kip Thorne, who was a faculty member there. He continues to have ties with Caltech, spending a month each year there since 1992.
Hawking's achievements were made despite the increasing paralysis caused by the ALS. By 1974, he was unable to feed himself or get out of bed. His speech became slurred so that he could be understood only by people who knew him well. In 1985, he caught pneumonia and had to have a tracheotomy, which made him unable to speak at all. A Cambridge scientist built a device that enables Hawking to write onto a computer with small movements of his body, and then have a voice synthesiser speak what he has typed.
In the late 1960s, he and his Cambridge friend and colleague, Roger Penrose, applied a new, complex mathematical model they had created from Albert Einstein's theory of general relativity. This led, in 1970, to Hawking proving the first of many singularity theorems; such theorems provide a set of sufficient conditions for the existence of a gravitational singularity in space-time. This work showed that, far from being mathematical curiosities which appear only in special cases, singularities are a fairly generic feature of general relativity.
He supplied a mathematical proof, along with Brandon Carter, Werner Israel and D. Robinson, of John Wheeler's no-hair theorem – namely, that any black hole is fully described by the three properties of mass, angular momentum, and electric charge.
Hawking also suggested upon analysis of gamma ray emissions that after the Big Bang, primordial mini black holes were formed. With Bardeen and Carter, he proposed the four laws of black hole mechanics, drawing an analogy with thermodynamics. In 1974, he calculated that black holes should thermally create and emit subatomic particles, known today as Bekenstein-Hawking radiation, until they exhaust their energy and evaporate.
In collaboration with Jim Hartle, Hawking developed a model in which the universe had no boundary in space-time, replacing the initial singularity of the classical Big Bang models with a region akin to the North Pole: one cannot travel north of the North Pole, as there is no boundary. While originally the no-boundary proposal predicted a closed universe, discussions with Neil Turok led to the realisation that the no-boundary proposal is also consistent with a universe which is not closed.
Along with Thomas Hertog at CERN, in 2006 Hawking proposed a theory of "top-down cosmology," which says that the universe had no unique initial state, and therefore it is inappropriate for physicists to attempt to formulate a theory that predicts the universe's current configuration from one particular initial state. Top-down cosmology posits that in some sense, the present "selects" the past from a superposition of many possible histories. In doing so, the theory suggests a possible resolution of the fine-tuning question: It is inevitable that we find our universe's present physical constants, as the current universe "selects" only those past histories that led to the present conditions. In this way, top-down cosmology provides an anthropic explanation for why we find ourselves in a universe that allows matter and life, without invoking an ensemble of multiple universes.
Hawking's many other scientific investigations have included the study of quantum cosmology, cosmic inflation, helium production in anisotropic Big Bang universes, large N cosmology, the density matrix of the universe, topology and structure of the universe, baby universes, Yang-Mills instantons and the S matrix, anti de Sitter space, quantum entanglement and entropy, the nature of space and time, including the arrow of time, spacetime foam, string theory, supergravity, Euclidean quantum gravity, the gravitational Hamiltonian, Brans-Dicke and Hoyle-Narlikar theories of gravitation, gravitational radiation, and wormholes.
At a George Washington University lecture in honour of NASA's fiftieth anniversary, Hawking theorised on the existence of extraterrestrial life, believing that "primitive life is very common and intelligent life is fairly rare."
Hawking was in the news in July 2004 for presenting a new theory about black holes which goes against his own long-held belief about their behaviour, thus losing a bet he made with Kip Thorne and John Preskill of Caltech. Classically, it can be shown that information crossing the event horizon of a black hole is lost to our universe, and that thus all black holes are identical beyond their mass, electrical charge and angular velocity (the "no hair theorem"). The problem with this theorem is that it implies the black hole will emit the same radiation regardless of what goes into it, and as a consequence that if a pure quantum state is thrown into a black hole, an "ordinary" mixed state will be returned. This runs counter to the rules of quantum mechanics and is known as the black hole information paradox.
At the celebration of his sixty-fifth birthday on 8 January 2007, Hawking announced his plan to take a zero-gravity flight in 2007 to prepare for a sub-orbital spaceflight in 2009 on Virgin Galactic's space service. Billionaire Richard Branson pledged to pay all expenses for the latter, costing an estimated £100,000. Stephen Hawking's zero-gravity flight in a "''Vomit Comet''" of Zero Gravity Corporation, during which he experienced weightlessness eight times, took place on 26 April 2007. He became the first quadriplegic to float in zero-gravity. This was the first time in forty years that he moved freely, without his wheelchair. The fee is normally US$3,750 for 10–15 plunges, but Hawking was not required to pay the fee. A bit of a futurist, Hawking was quoted before the flight saying: }} In an interview with ''The Daily Telegraph'', he suggested that space was the Earth's long term hope. He continued this theme at a 2008 Charlie Rose interview.
Stephen Hawking is severely disabled by a motor neurone disease known as Amyotrophic lateral sclerosis (ALS), sometimes known as Lou Gehrig's disease. Hawking's illness is markedly different from typical ALS because if confirmed, Hawking's case would make for the most protracted case ever documented. A survival for more than ten years after diagnosis is uncommon for ALS; the longest documented durations, other than Hawking's, are 32 and 39 years and these cases were termed benign because of the lack of the typical progressive course.
When he was young, he enjoyed riding horses. At Oxford, he coxed a rowing team, which, he stated, helped relieve his immense boredom at the university. Symptoms of the disorder first appeared while he was enrolled at University of Cambridge; he lost his balance and fell down a flight of stairs, hitting his head. Worried that he would lose his genius, he took the Mensa test to verify that his intellectual abilities were intact. The diagnosis of motor neurone disease came when Hawking was 21, shortly before his first marriage, and doctors said he would not survive more than two or three years. Hawking gradually lost the use of his arms, legs, and voice, and as of 2009 has been almost completely paralysed.
During a visit to the research centre CERN in Geneva in 1985, Hawking contracted pneumonia, which in his condition was life-threatening as it further restricted his already limited respiratory capacity. He had an emergency tracheotomy, and as a result lost what remained of his ability to speak. He has since used an electronic voice synthesiser to communicate.
The DECtalk DTC01 voice synthesiser he uses, which has an American English accent, is no longer being produced. Asked why he has still kept it after so many years, Hawking mentioned that he has not heard a voice he likes better and that he identifies with it. Hawking is said to be looking for a replacement since, aside from being obsolete, the synthesiser is both large and fragile by current standards. As of mid 2009, he was said to be using NeoSpeech's VoiceText speech synthesiser.
In Hawking's many media appearances, he appears to speak fluently through his synthesiser, but in reality, it is a tedious drawn-out process. Hawking's setup uses a predictive text entry system, which requires only the first few characters in order to auto-complete the word, but as he is only able to use his cheek for data entry, constructing complete sentences takes time. His speeches are prepared in advance, but having a live conversation with him provides insight as to the complexity and work involved. During a TED Conference talk, it took him seven minutes to answer a question.
He describes himself as lucky, despite his disease. Its slow progression has allowed him time to make influential discoveries and has not hindered him from having, in his own words, "a very attractive family." When his wife, Jane, was asked why she decided to marry a man with a three-year life expectancy, she responded, "Those were the days of atomic gloom and doom, so we all had a rather short life expectancy." On 20 April 2009, Cambridge University released a statement saying that Hawking was "very ill" with a chest infection, and was admitted to Addenbrooke's Hospital. The following day, it was reported that his new condition was "comfortable" and he would make a full recovery from the infection.
Hawking supports the children's charity SOS Children's Villages UK.
In 1999, Jane Hawking published a memoir, ''Music to Move the Stars'', detailing the marriage and his breakdown; in 2010 she published a revised version, ''Travelling to Infinity, My Life with Stephen''. Hawking's daughter, Lucy, is a novelist. Their oldest son, Robert, emigrated to the United States, married, and has a son. After a period of estrangement, Hawking and his first family were reconciled in 2007.
His view on how to live life is to "seek the greatest value of our action".
Hawking was asked about his IQ in a 2004 newspaper interview, and replied, "I have no idea. People who boast about their I.Q. are losers." Yet when asked "Are you saying you are not a genius?", Hawking replied "I hope I'm near the upper end of the range."
Hawking strongly opposed the US-led Iraq War, calling it "a war crime" and "based on lies". In 2004, he personally attended a demonstration against the war in Trafalgar Square, and participated in a public reading of the names of Iraqi war victims.
His ex-wife, Jane, said during their divorce proceedings that he was an atheist. Hawking has stated that he is "not religious in the normal sense" and he believes that "the universe is governed by the laws of science. The laws may have been decreed by God, but God does not intervene to break the laws." In an interview published in ''The Guardian'' newspaper, Hawking regarded the concept of Heaven as a myth, stating that there is "no heaven or afterlife" and that such a notion was a "fairy story for people afraid of the dark."
Hawking contrasted religion and science in 2010, saying: "There is a fundamental difference between religion, which is based on authority, [and] science, which is based on observation and reason. Science will win because it works."
;Dated
Category:1942 births Category:Academics of the University of Cambridge Category:Adams Prize recipients Category:Albert Einstein Medal recipients Category:Alumni of Trinity Hall, Cambridge Category:Alumni of University College, Oxford Category:Calculating prodigies Category:Commanders of the Order of the British Empire Category:Cosmologists Category:English astronomers Category:English theoretical physicists Category:English science writers Category:Fellows of Gonville and Caius College, Cambridge Category:Fellows of the Royal Society Category:People educated at St Albans School, Hertfordshire Category:Honorary Fellows of University College, Oxford Category:Living people Category:Lucasian Professors of Mathematics Category:Members of the Department of Applied Mathematics and Theoretical Physics Category:Members of the United States National Academy of Sciences Category:Members of the Order of the Companions of Honour Category:Members of the Pontifical Academy of Sciences Category:People from Oxford Category:People from St Albans Category:People with motor neurone disease Category:Presidential Medal of Freedom recipients Category:Recipients of the Copley Medal Category:Recipients of the Gold Medal of the Royal Astronomical Society Category:Religious skeptics Category:Wolf Prize in Physics laureates Category:20th-century philosophers Category:21st-century philosophers Category:People educated at St Albans High School for Girls
af:Stephen Hawking ar:ستيفن هوكينج az:Stiven Hokinq bn:স্টিফেন হকিং zh-min-nan:Stephen Hawking be:Стывен Уільям Хокінг bg:Стивън Хокинг bs:Stephen Hawking ca:Stephen Hawking cs:Stephen Hawking cy:Stephen Hawking da:Stephen Hawking de:Stephen Hawking et:Stephen Hawking el:Στήβεν Χώκινγκ es:Stephen Hawking eo:Stephen Hawking ext:Stephen Hawking eu:Stephen Hawking fa:استیون هاوکینگ fr:Stephen Hawking ga:Stephen Hawking gl:Stephen Hawking ko:스티븐 호킹 hi:स्टीफन हॉकिंग hr:Stephen Hawking io:Stephen Hawking id:Stephen Hawking is:Stephen Hawking it:Stephen Hawking he:סטיבן הוקינג jv:Stephen Hawking kn:ಸ್ಟೀಫನ್ ಹಾಕಿಂಗ್ ka:სტივენ ჰოუკინგი ht:Stephen Hawking la:Stephanus Hawking lv:Stīvens Hokings lb:Stephen Hawking lt:Stephen Hawking hu:Stephen Hawking mk:Стивен Хокинг ml:സ്റ്റീഫൻ ഹോക്കിങ് mr:स्टीफन हॉकिंग ms:Stephen Hawking mn:Стивен Хокинг my:စတီဖင်ဟော့ကင်း nah:Stephen Hawking nl:Stephen Hawking ja:スティーヴン・ホーキング no:Stephen Hawking nn:Stephen Hawking pnb:سٹیفن ہاکنگ pl:Stephen Hawking pt:Stephen Hawking ro:Stephen Hawking ru:Хокинг, Стивен Уильям sq:Stephen Hawking simple:Stephen Hawking sk:Stephen Hawking sl:Stephen Hawking sr:Стивен Хокинг sh:Stephen Hawking fi:Stephen Hawking sv:Stephen Hawking tl:Stephen Hawking ta:ஸ்டீபன் ஹோக்கிங் te:స్టీఫెన్ హాకింగ్ th:สตีเฟน ฮอว์คิง tg:Стивен Ҳокинг tr:Stephen Hawking uk:Стівен Гокінг ur:سٹیفن ہاکنگ vi:Stephen Hawking war:Stephen Hawking yi:סטיווען האקינג zh-yue:霍金 bat-smg:Stephen Hawking zh:史蒂芬·霍金
This text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
name | David Gabai |
---|---|
nationality | |
fields | Mathematics |
workplaces | Princeton UniversityCaltech |
alma mater | Princeton University MIT |
doctoral advisor | William Thurston |
Known for | low-dimensional topology |
awards | Oswald Veblen Prize in Geometry (2004) }} |
David Gabai received his S.B. degree from the MIT in 1976 and his Ph.D. from Princeton in 1980 under the direction of William Thurston. During his Ph.D., he obtained foundational results on the foliations of 3-manifolds; these results are the basis of many research areas in geometric topology now.
After positions at Harvard and U Penn, he spent most of the years between 1986–2001 at Caltech, and has been at Princeton University since 2001.
In 2004, David Gabai was awarded the Oswald Veblen Prize in Geometry, which is one of the most prestigious prizes in geometric topology, given every 3 years by the American Mathematical Society. In 2011, he was elected to the United States National Academy of Sciences.
David Gabai has played a key role in the field of topology of 3-manifolds in the last 3 decades. Some of the foundational results he and his collaborators have proved are as follows: Existence of taut foliation in 3-manifolds, Property R Conjecture, foundation of essential laminations, Seifert fiber space conjecture, rigidity of homotopy hyperbolic 3-manifolds, weak hyperbolization for 3-manifolds with genuine lamination, Smale Conjecture for hyperbolic 3-manifolds, Marden's Tameness Conjecture, Weeks's manifold being the minimum volume closed hyperbolic 3-manifold.
Category:Year of birth missing (living people) Category:Living people Category:Topologists Category:Princeton University faculty Category:Members of the United States National Academy of Sciences
de:David Gabai
This text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
He (jointly with Jun Li) constructed the moduli spaces of maps from curves in both algebraic geometry and symplectic geometry and studied the obstruction theory on these moduli spaces. He also (jointly with Y. Ruan) showed that the quantum cohomology ring of a symplectic manifold is associative.
In 2006, together with John Morgan of Columbia University, amongst others, Tian helped verify the proof of the Poincaré conjecture given by Grigori Perelman.
Tian, Gang. Smoothness of the universal deformation space of compact Calabi-Yau manifolds and its Petersson-Weil metric. Mathematical aspects of string theory (San Diego, Calif., 1986), 629--646, Adv. Ser. Math. Phys., 1, World Sci. Publishing, Singapore, 1987.
Tian, Gang. On Kähler-Einstein metrics on certain Kähler manifolds with $C\sb 1(M)>0$. Invent. Math. 89 (1987), no. 2, 225--246.
Tian, G.; Yau, Shing-Tung. Complete Kähler manifolds with zero Ricci curvature. I. J. Amer. Math. Soc. 3 (1990), no. 3, 579--609.
Tian, G. On Calabi's conjecture for complex surfaces with positive first Chern class. Invent. Math. 101 (1990), no. 1, 101--172.
Tian, Gang. On a set of polarized Kähler metrics on algebraic manifolds. J. Differential Geom. 32 (1990), no. 1, 99--130.
Ruan, Yongbin; Tian, Gang. A mathematical theory of quantum cohomology. J. Differential Geom. 42 (1995), no. 2, 259--367.
Tian, Gang. Kähler-Einstein metrics with positive scalar curvature. Invent. Math. 130 (1997), no. 1, 1--37.
Ruan, Yongbin; Tian, Gang. Higher genus symplectic invariants and sigma models coupled with gravity. Invent. Math. 130 (1997), no. 3, 455--516.
Li, Jun; Tian, Gang. Virtual moduli cycles and Gromov-Witten invariants of algebraic varieties. J. Amer. Math. Soc. 11 (1998), no. 1, 119--174.
Liu, Gang; Tian, Gang. Floer homology and Arnold conjecture. J. Differential Geom. 49 (1998), no. 1, 1--74.
Liu, Xiaobo; Tian, Gang. Virasoro constraints for quantum cohomology. J. Differential Geom. 50 (1998), no. 3, 537--590.
Tian, Gang. Gauge theory and calibrated geometry. I. Ann. of Math. (2) 151 (2000), no. 1, 193--268.
Tian, Gang; Zhu, Xiaohua. Uniqueness of Kähler-Ricci solitons. Acta Math. 184 (2000), no. 2, 271--305.
Cheeger, J.; Colding, T. H.; Tian, G. On the singularities of spaces with bounded Ricci curvature. Geom. Funct. Anal. 12 (2002), no. 5, 873--914.
Tao, Terence; Tian, Gang. A singularity removal theorem for Yang-Mills fields in higher dimensions. J. Amer. Math. Soc. 17 (2004), no. 3, 557--593.
Tian, Gang; Viaclovsky, Jeff. Bach-flat asymptotically locally Euclidean metrics. Invent. Math. 160 (2005), no. 2, 357--415.
Cheeger, Jeff; Tian, Gang. Curvature and injectivity radius estimates for Einstein 4-manifolds. J. Amer. Math. Soc. Vol. 19, No. 2 (2006), 487--525.
Morgan, John; Tian, Gang. Ricci flow and the Poincaré conjecture. Clay Mathematics Monographs, 3. American Mathematical Society, Providence, RI; Clay Mathematics Institute, Cambridge, MA, 2007, 525pp.
Song, Jian; Tian, Gang. The Kähler-Ricci flow on surfaces of positive Kodaira dimension. Invent. Math. 170 (2007), no. 3, 609--653.
Chen, X. X.; Tian, G. Geometry of Kähler metrics and foliations by holomorphic discs. Publ. Math. Inst. Hautes Études Sci. No. 107 (2008), 1--107.
Kołodziej, Sławomir; Tian, Gang A uniform $L^\infty$L∞ estimate for complex Monge-Ampère equations. Math. Ann. 342 (2008), no. 4, 773–787.
Mundet i Riera, I.; Tian, G. A compactification of the moduli space of twisted holomorphic maps. Adv. Math. 222 (2009), no. 4, 1117–1196.
Rivière, Tristan; Tian, Gang The singular set of 1-1 integral currents. Ann. of Math. (2) 169 (2009), no. 3, 741–794.
Tian, Gang Finite-time singularity of Kähler-Ricci flow. Discrete Contin. Dyn. Syst. 28 (2010), no. 3, 1137–1150.
Xiaodong Cao, MIT, 2002;
Sandra Francisco, MIT, 2005;
Zuoliang Hou, MIT, 2004;Ljudmila Kamenova, MIT, 2006;
Peng Lu State, University of New York at Stony Brook, 1996;
Zhiqin Lu, New York University, 1997;Dragos Oprea, MIT, 2005;
Yanir Rubinstein, MIT, 2008;
Sema Salur, Michigan State University, 2000;Bianca Santoro, MIT, 2006;
Natasa Sesum, MIT, 2004;Jake Solomon, MIT, 2006;
Michael Usher, MIT, 2004;Lijing Wang, MIT, 2003;
Hao Wu, MIT, 2004;
Zhiyu Wu, Columbia University, 1998;
Baozhong Yang, MIT, 2000;
Zhou Zhang, MIT, 2006;
Hans-Joachim Hein, Princeton, 2010;
Richard Bamler, Princeton, 2011;
Chi Li, Princeton, 2011;
Mohammad Farajzadeh Tehrani, Princeton 2011;
Giulia Saccà, Princeton, 2012;
Guangbo Xu, Princeton 2012;
Category:1958 births Category:20th-century mathematicians Category:21st-century mathematicians Category:Chinese mathematicians Category:Harvard University alumni Category:Members of the Chinese Academy of Sciences Category:Peking University alumni Category:Peking University faculty Category:Fellows of the American Academy of Arts and Sciences Category:Princeton University faculty Category:Living people
de:Gang Tian ja:田剛 pt:Gang Tian zh:田刚This text is licensed under the Creative Commons CC-BY-SA License. This text was originally published on Wikipedia and was developed by the Wikipedia community.
The World News (WN) Network, has created this privacy statement in order to demonstrate our firm commitment to user privacy. The following discloses our information gathering and dissemination practices for wn.com, as well as e-mail newsletters.
We do not collect personally identifiable information about you, except when you provide it to us. For example, if you submit an inquiry to us or sign up for our newsletter, you may be asked to provide certain information such as your contact details (name, e-mail address, mailing address, etc.).
When you submit your personally identifiable information through wn.com, you are giving your consent to the collection, use and disclosure of your personal information as set forth in this Privacy Policy. If you would prefer that we not collect any personally identifiable information from you, please do not provide us with any such information. We will not sell or rent your personally identifiable information to third parties without your consent, except as otherwise disclosed in this Privacy Policy.
Except as otherwise disclosed in this Privacy Policy, we will use the information you provide us only for the purpose of responding to your inquiry or in connection with the service for which you provided such information. We may forward your contact information and inquiry to our affiliates and other divisions of our company that we feel can best address your inquiry or provide you with the requested service. We may also use the information you provide in aggregate form for internal business purposes, such as generating statistics and developing marketing plans. We may share or transfer such non-personally identifiable information with or to our affiliates, licensees, agents and partners.
We may retain other companies and individuals to perform functions on our behalf. Such third parties may be provided with access to personally identifiable information needed to perform their functions, but may not use such information for any other purpose.
In addition, we may disclose any information, including personally identifiable information, we deem necessary, in our sole discretion, to comply with any applicable law, regulation, legal proceeding or governmental request.
We do not want you to receive unwanted e-mail from us. We try to make it easy to opt-out of any service you have asked to receive. If you sign-up to our e-mail newsletters we do not sell, exchange or give your e-mail address to a third party.
E-mail addresses are collected via the wn.com web site. Users have to physically opt-in to receive the wn.com newsletter and a verification e-mail is sent. wn.com is clearly and conspicuously named at the point of
collection.If you no longer wish to receive our newsletter and promotional communications, you may opt-out of receiving them by following the instructions included in each newsletter or communication or by e-mailing us at michaelw(at)wn.com
The security of your personal information is important to us. We follow generally accepted industry standards to protect the personal information submitted to us, both during registration and once we receive it. No method of transmission over the Internet, or method of electronic storage, is 100 percent secure, however. Therefore, though we strive to use commercially acceptable means to protect your personal information, we cannot guarantee its absolute security.
If we decide to change our e-mail practices, we will post those changes to this privacy statement, the homepage, and other places we think appropriate so that you are aware of what information we collect, how we use it, and under what circumstances, if any, we disclose it.
If we make material changes to our e-mail practices, we will notify you here, by e-mail, and by means of a notice on our home page.
The advertising banners and other forms of advertising appearing on this Web site are sometimes delivered to you, on our behalf, by a third party. In the course of serving advertisements to this site, the third party may place or recognize a unique cookie on your browser. For more information on cookies, you can visit www.cookiecentral.com.
As we continue to develop our business, we might sell certain aspects of our entities or assets. In such transactions, user information, including personally identifiable information, generally is one of the transferred business assets, and by submitting your personal information on Wn.com you agree that your data may be transferred to such parties in these circumstances.