Grigori Perelman  

Born  
Nationality  Russian 
Citizenship  Russia 
Alma mater  Leningrad State University (PhD) 
Known for 

Awards 

Scientific career  
Fields  Differential geometry Geometric analysis Geometric topology 
Thesis  Saddle Surfaces in Euclidean Spaces (1990) 
Doctoral advisor 
Grigori Yakovlevich Perelman (Russian: Григорий Яковлевич Перельман, IPA: [ɡrʲɪˈɡorʲɪj ˈjakəvlʲɪvʲɪtɕ pʲɪrʲɪlʲˈman] (listen); born 13 June 1966) is a Russian mathematician who is known for his contributions to the fields of geometric analysis, Riemannian geometry, and geometric topology. He is widely regarded as one of the greatest living mathematicians.^{[1]}^{[2]}^{[3]}
In the 1990s, partly in collaboration with Yuri Burago, Mikhael Gromov, and Anton Petrunin, he made contributions to the study of Alexandrov spaces. In 1994, he proved the soul conjecture in Riemannian geometry, which had been an open problem for the previous 20 years. In 2002 and 2003, he developed new techniques in the analysis of Ricci flow, and proved the Poincaré conjecture and Thurston's geometrization conjecture, the former of which had been a famous open problem in mathematics for the past century. The full details of Perelman's work were filled in and explained by various authors over the following several years.
In August 2006, Perelman was offered the Fields Medal^{[4]} for "his contributions to geometry and his revolutionary insights into the analytical and geometric structure of the Ricci flow", but he declined the award, stating: "I'm not interested in money or fame; I don't want to be on display like an animal in a zoo."^{[5]} On 22 December 2006, the scientific journal Science recognized Perelman's proof of the Poincaré conjecture as the scientific "Breakthrough of the Year", the first such recognition in the area of mathematics.^{[6]}
On 18 March 2010, it was announced that he had met the criteria to receive the first Clay Millennium Prize^{[7]} for resolution of the Poincaré conjecture. On 1 July 2010, he rejected the prize of one million dollars, saying that he considered the decision of the board of the Clay Institute to be unfair, in that his contribution to solving the Poincaré conjecture was no greater than that of Richard S. Hamilton, the mathematician who pioneered the Ricci flow partly with the aim of attacking the conjecture.^{[8]}^{[9]} He had previously rejected the prestigious prize of the European Mathematical Society in 1996.^{[10]}
Early life and education
Grigori Yakovlevich Perelman was born in Leningrad, Soviet Union (now Saint Petersburg, Russia) on 13 June 1966, to Jewish parents,^{[11]}^{[12]}^{[13]} Yakov (who now lives in Israel)^{[11]} and Lyubov (who still lives in Saint Petersburg with Grigori).^{[11]} Grigori's mother Lyubov gave up graduate work in mathematics to raise him. Grigori's mathematical talent became apparent at the age of ten, and his mother enrolled him in Sergei Rukshin's afterschool mathematics training program.^{[14]}
His mathematical education continued at the Leningrad Secondary School 239, a specialized school with advanced mathematics and physics programs. Grigori excelled in all subjects except physical education.^{[15]} In 1982, as a member of the Soviet Union team competing in the International Mathematical Olympiad, an international competition for high school students, he won a gold medal, achieving a perfect score.^{[16]} He continued as a student of The School of Mathematics and Mechanics at the Leningrad State University, without admission examinations and enrolled to the university.^{[16]}
After completing his PhD in 1990, Perelman began work at the Leningrad Department of Steklov Institute of Mathematics of the USSR Academy of Sciences, where his advisors were Aleksandr Aleksandrov and Yuri Burago. In the late 1980s and early 1990s, with a strong recommendation from the geometer Mikhail Gromov,^{[17]} Perelman obtained research positions at several universities in the United States. In 1991, Perelman won the Young Mathematician Prize of the St. Petersburg Mathematical Society for his work on Aleksandrov's spaces of curvature bounded from below.^{[18]} In 1992, he was invited to spend a semester each at the Courant Institute in New York University and Stony Brook University where he began work on manifolds with lower bounds on Ricci curvature. From there, he accepted a twoyear Miller Research Fellowship at the University of California, Berkeley in 1993. After having proved the soul conjecture in 1994, he was offered jobs at several top universities in the US, including Princeton and Stanford, but he rejected them all and returned to the Steklov Institute in Saint Petersburg in the summer of 1995 for a researchonly position.^{[14]}
Early research
Convex geometry
In his undergraduate studies, Perelman dealt with issues in the field of convex geometry. His first published article studied the combinatorial structures arising from intersections of convex polyhedra.^{[P85]} With I. V. Polikanova, he established a measuretheoretic formulation of Helly's theorem.^{[PP86]} In 1987, the year he began graduate studies, he published an article controlling the size of circumscribed cylinders by that of inscribed spheres.^{[P87]}
Negatively curved hypersurfaces
Surfaces of negative curvature were the subject of Perelman's graduate studies. His first result was on the possibility of prescribing the structure of negativelycurved polyhedral surfaces in threedimensional Euclidean space. He proved that any such metric on the plane which is complete can be continuously immersed as a polyhedral surface.^{[P88]} Later, he constructed an example of a smooth hypersurface of fourdimensional Euclidean space which is complete and has Gaussian curvature negative and bounded away from zero. Previous examples of such surfaces were known, but Perelman's was the first to exhibit the saddle property on nonexistence of locally strictly supporting hyperplanes.^{[P89]} As such, his construction provided further obstruction to the extension of a wellknown theorem of Nikolai Efimov to higher dimensions.^{[19]}
Alexandrov spaces
Perelman's first works to a have a major impact on the mathematical literature were in the field of Alexandrov spaces, the concept of which dates back to the 1950s. In a very wellknown paper coauthored with Yuri Burago and Mikhael Gromov, Perelman established the modern foundations of this field, with the notion of Gromov–Hausdorff convergence as an organizing principle.^{[BGP92]} In a followup unpublished paper, Perelman proved his "stability theorem," asserting that in the collection of all Alexandrov spaces with a fixed curvature bound, all elements of any sufficiently small metric ball around a compact space are mutually homeomorphic.^{[P91]} Vitali Kapovitch, who described Perelman's article as being "very hard to read," later wrote a detailed version of Perelman's proof, making use of some further simplifications.
Perelman developed a version of Morse theory on Alexandrov spaces.^{[P93]} Despite the lack of smoothness in Alexandrov spaces, Perelman and Anton Petrunin were able to consider the gradient flow of certain functions, in unpublished work.^{[PP95]} They also introduced the notion of an "extremal subset" of Alexandrov spaces, and showed that the interiors of certain extremal subsets define a stratification of the space by topological manifolds.^{[PP93]} In further unpublished work, Perelman studied DC functions (difference of concave functions) on Alexandrov spaces and established that the set of regular points has the structure of a manifold modeled on DC functions.^{[P95d]}
For his work on Alexandrov spaces, Perelman was recognized with an invited lecture at the 1994 International Congress of Mathematicians.^{[P95a]}
Comparison geometry
In 1972, Jeff Cheeger and Detlef Gromoll established their important soul theorem. It asserts that every complete Riemannian metric of nonnegative sectional curvature has a compact nonnegatively curved submanifold, called a soul, whose normal bundle is diffeomorphic to the original space. From the perspective of homotopy theory, this says in particular that every complete Riemannian metric of nonnegative sectional curvature may be taken to be closed. Cheeger and Gromoll conjectured that if the curvature is strictly positive somewhere, then the soul can be taken to be a single point, and hence that the original space must be diffeomorphic to Euclidean space. In 1994, Perelman gave a short proof of Cheeger and Gromoll's conjecture by establishing that, under the condition of nonnegative sectional curvature, Sharafutdinov's retraction is a submersion.^{[P94b]} Perelman's theorem is significant in establishing a topological obstruction to deforming a nonnegatively curved metric to one which is positively curved, even at a single point.
Some of Perelman's work dealt with the construction of various interesting Riemannian manifolds with positive Ricci curvature. He found Riemannian metrics on the connected sum of arbitrarily many complex projective planes with positive Ricci curvature, bounded diameter, and volume bounded away from zero.^{[P97b]} Also, he found an explicit complete metric on fourdimensional Euclidean space with positive Ricci curvature and Euclidean volume growth, and such that the asymptotic cone is nonuniquely defined.^{[P97c]}
Geometrization and Poincaré conjectures
The problems
The Poincaré conjecture, proposed by mathematician Henri Poincaré in 1904, was throughout the 20th century regarded as a key problem in topology. On the 3sphere, defined as the set of points at unit length from the origin in fourdimensional Euclidean space, any loop can be contracted into a point. Poincaré suggested that a converse might be true: if a closed threedimensional manifold has the property that any loop can be contracted into a point, then it must be topologically equivalent to a 3sphere. Stephen Smale proved a highdimensional analogue of Poincaré's conjecture in 1961, and Michael Freedman proved the fourdimensional version in 1982.^{[20]}^{[21]} Despite their work, the case of threedimensional spaces remained completely unresolved. Moreover, Smale and Freedman's methods have had no impact on the threedimensional case, as their topological manipulations, moving "problematic regions" out of the way without interfering with other regions, seem to require high dimensions in order to work.
In 1982, William Thurston developed a novel viewpoint, making the Poincaré conjecture into a small special case of a hypothetical systematic structure theory of topology in three dimensions. His proposal, known as the Thurston geometrization conjecture, posited that given any closed threedimensional manifold whatsoever, there is some collection of twodimensional spheres and tori inside of the manifold which disconnect the space into separate pieces, each of which can be endowed with a uniform geometric structure.^{[22]} Thurston was able to prove his conjecture under some provisional assumptions. In John Morgan's view, it was only with Thurston's systematic viewpoint that most topologists came to believe that the Poincaré conjecture would be true.^{[23]}
At the same time that Thurston published his conjecture, Richard Hamilton introduced his theory of the Ricci flow. Hamilton's Ricci flow is a prescription, defined by a partial differential equation formally analogous to the heat equation, for how to deform a Riemannian metric on a manifold. The heat equation, such as when applied in the sciences to physical phenomena such as temperature, models how concentrations of extreme temperatures will spread out until a uniform temperature is achieved throughout an object. In three seminal articles published in the 1980s, Hamilton proved that his equation achieved analogous phenomena, spreading extreme curvatures and uniformizing a Riemannian metric, in certain geometric settings.^{[24]}^{[25]}^{[26]} As a byproduct, he was able to prove some new and striking theorems in the field of Riemannian geometry.
Despite formal similarities, Hamilton's equations are significantly more complex and nonlinear than the heat equation, and it is impossible that such uniformization is achieved without contextual assumptions. In completely general settings, it is inevitable that "singularities" occur, meaning that curvature accumulates to infinite levels after a finite amount of "time" has elapsed. Following ShingTung Yau's suggestion that a detailed understanding of these singularities could be topologically meaningful, and in particular that their locations might identify the spheres and tori in Thurston's conjecture, Hamilton began a systematic analysis.^{[27]} Throughout the 1990s, he found a number of new technical results and methods,^{[28]} culminating in a 1997 publication constructing a "Ricci flow with surgery" for fourdimensional spaces.^{[29]} As an application of his construction, Hamilton was able to settle a fourdimensional curvaturebased analogue of the Poincaré conjecture. Yau has identified this article as one of the most important in the field of geometric analysis, saying that with its publication it became clear that Ricci flow could be powerful enough to settle the Thurston conjecture.^{[30]} The key of Hamilton's analysis was a quantitative understanding of how singularities occur in his fourdimensional setting; the most outstanding difficulty was the quantitative understanding of how singularities occur in threedimensional settings. Although Hamilton was unable to resolve this issue, in 1999 he published work on Ricci flow in three dimensions, showing that if a threedimensional version of his surgery techniques could be developed, and if a certain conjecture on the longtime behavior of Ricci flow could be established, then Thurston's conjecture would be resolved.^{[31]} This became known as the Hamilton program.
Perelman's work
In November 2002 and March 2003, Perelman posted two preprints to arXiv, in which he claimed to have outlined a proof of Thurston's conjecture.^{[P02]}^{[P03a]} In a third paper posted in July 2003, Perelman outlined an additional argument, sufficient for proving the Poincaré conjecture (but not the Thurston conjecture), the point being to avoid the most technical work in his second preprint.^{[P03b]} Making use of the AlmgrenPitts minmax theory from the field of geometric measure theory, Tobias Colding and William Minicozzi provided a completely alternative proof of the results in Perelman's third preprint.^{[32]}^{[33]}^{[34]}
Perelman's first preprint contained two primary results, both to do with Ricci flow. The first, valid in any dimension, was based on a novel adaptation of Peter Li and ShingTung Yau's differential Harnack inequalities to the setting of Ricci flow.^{[35]} By carrying out the proof of the BishopGromov inequality for the resulting Li−Yau length functional, Perelman established his celebrated "noncollapsing theorem" for Ricci flow, asserting that local control of the size of the curvature implies control of volumes. The significance of the noncollapsing theorem is that volume control is one of the preconditions of Hamilton's compactness theorem. As a consequence, Hamilton's compactness and the corresponding existence of subsequential limits could be applied somewhat freely.
The "canonical neighborhoods theorem" is the second main result of Perelman's first preprint. In this theorem, Perelman achieved the quantitative understanding of singularities of threedimensional Ricci flow which had eluded Hamilton. Roughly speaking, Perelman showed that on a microscopic level, every singularity looks either like a cylinder collapsing to its axis, or a sphere collapsing to its center. Perelman's proof of his canonical neighborhoods theorem is a highly technical achievement, based upon extensive arguments by contradiction in which Hamilton's compactness theorem (as facilitated by Perelman's noncollapsing theorem) is applied to construct selfcontradictory manifolds.
Other results in Perelman's first preprint include the introduction of certain monotonic quantities and a "pseudolocality theorem" which relates curvature control and isoperimetry. However, despite being major results in the theory of Ricci flow, these results were not used in the rest of his work.
The first half of Perelman's second preprint, in addition to fixing some incorrect statements and arguments from the first paper, used his canonical neighborhoods theorem to construct a Ricci flow with surgery in three dimensions, systematically excising singular regions as they develop. As an immediate corollary of his construction, Perelman resolved a major conjecture on the topological classification in three dimensions of closed manifolds which admit metrics of positive scalar curvature. His third preprint (or alternatively Colding and Minicozzi's work) showed that on any space satisfying the assumptions of the Poincaré conjecture, the Ricci flow with surgery exists only for finite time, so that the infinitetime analysis of Ricci flow is irrelevant. The construction of Ricci flow with surgery has the Poincaré conjecture as a corollary.
In order to settle the Thurston conjecture, the second half of Perelman's second preprint is devoted to an analysis of Ricci flows with surgery, which may exist for infinite time. Perelman was unable to resolve Hamilton's 1999 conjecture on longtime behavior, which would make Thurston's conjecture another corollary of the existence of Ricci flow with surgery. Nonetheless, Perelman was able to adapt Hamilton's arguments to the precise conditions of his new Ricci flow with surgery. The end of Hamilton's argument made use of Jeff Cheeger and Mikhael Gromov's theorem characterizing collapsing manifolds. In Perelman's adaptation, he required use of a new theorem characterizing manifolds in which collapsing is only assumed on a local level. In his preprint, he said the proof of his theorem would be established in another paper, but he did not then release any further details. Proofs were later published by Takashi Shioya and Takao Yamaguchi,^{[36]} John Morgan and Gang Tian,^{[37]} Jianguo Cao and Jian Ge,^{[38]} and Bruce Kleiner and John Lott.^{[39]}
Verification
Perelman's preprints quickly gained the attention of the mathematical community, although they were widely seen as hard to understand since they had been written somewhat tersely. Against the usual style in academic mathematical publications, many technical details had been omitted. It was soon apparent that Perelman had made major contributions to the foundations of Ricci flow, although it was not immediately clear to the mathematical community that these contributions were sufficient to prove the geometrization conjecture or the Poincaré conjecture.
In April 2003, Perelman visited the Massachusetts Institute of Technology, Princeton University, Stony Brook University, Columbia University, and New York University to give short series of lectures on his work, and to clarify some details for experts in the relevant fields. In the years afterwards, three detailed expositions appeared, discussed below. Since then, various parts of Perelman's work have also appeared in a number of textbooks and expository articles.
 In June 2003, Bruce Kleiner and John Lott, both then of the University of Michigan, posted notes on Lott's website which, section by section, filled in details of Perelman's first preprint. In September 2004, their notes were updated to include Perelman's second preprint. Following further revisions and corrections, they posted a version to arXiv on 25 May 2006, a modified version of which was published in the academic journal Geometry & Topology in 2008.^{[40]} At the 2006 International Congress of Mathematicians, Lott said "It has taken us some time to examine Perelman's work. This is partly due to the originality of Perelman's work and partly to the technical sophistication of his arguments. All indications are that his arguments are correct." In the introduction to their article, Kleiner and Lott explained
Perelman's proofs are concise and, at times, sketchy. The purpose of these notes is to provide the details that are missing in [Perelman's first two preprints]... Regarding the proofs, [Perelman's papers] contain some incorrect statements and incomplete arguments, which we have attempted to point out to the reader. (Some of the mistakes in [Perelman's first paper] were corrected in [Perelman's second paper].) We did not find any serious problems, meaning problems that cannot be corrected using the methods introduced by Perelman.
 Since its 2008 publication, Kleiner and Lott's article has subsequently been revised twice for corrections, such as for an incorrect statement of Hamilton's important "compactness theorem" for Ricci flow. The latest revision to their article was in 2013.
 In June 2006, the Asian Journal of Mathematics published an article by HuaiDong Cao of Lehigh University and Zhu Xiping of Sun Yatsen University, giving a complete description of Perelman's proof of the Poincaré and the geometrization conjectures. Unlike Kleiner and Lott's article, which was structured as a collection of annotations to Perelman's papers, Cao and Zhu's article was aimed directly towards explaining the proofs of the Poincaré conjecture and geometrization conjecture. In their introduction, they explain
In this paper, we shall present the HamiltonPerelman theory of Ricci flow. Based on it, we shall give the first written account of a complete proof of the Poincaré conjecture and the geometrization conjecture of Thurston. While the complete work is an accumulated efforts of many geometric analysts, the major contributors are unquestionably Hamilton and Perelman. [...] In this paper, we shall give complete and detailed proofs [...] especially of Perelman's work in his second paper in which many key ideas of the proofs are sketched or outlined but complete details of the proofs are often missing. As we pointed out before, we have to substitute several key arguments of Perelman by new approaches based on our study, because we were unable to comprehend these original arguments of Perelman which are essential to the completion of the geometrization program.
 Based also upon the title "A Complete Proof of the Poincaré and Geometrization Conjectures – Application of the HamiltonPerelman Theory of Ricci Flow" and the phrase "This proof should be considered as the crowning achievement of the HamiltonPerelman theory of Ricci flow" from the abstract, some people interpreted Cao and Zhu to be taking credit from Perelman for themselves.^{[41]} When asked about the issue, Perelman said that he couldn't see any new contribution by Cao and Zhu and that they "did not quite understand the argument and reworked it."^{[41]} Additionally, one of the pages of Cao and Zhu's article was essentially identical to one from Kleiner and Lott's 2003 posting. In a published erratum,^{[42]} Cao and Zhu attributed this to an oversight, saying that in 2003 they had taken down notes from the initial version of Kleiner and Lott's notes, and in their 2006 writeup had not realized the proper source of the notes. They posted a revised version to arXiv^{[43]} with revisions in their phrasing and in the relevant page of the proof.
 In July 2006, John Morgan of Columbia University and Gang Tian of the Massachusetts Institute of Technology posted a paper on arXiv in which they provided a detailed presentation of Perelman's proof of the Poincaré conjecture.^{[44]} Unlike KleinerLott and CaoZhu's expositions, Morgan and Tian's also deals with Perelman's third paper. On 24 August 2006, Morgan delivered a lecture at the ICM in Madrid on the Poincaré conjecture, in which he declared that Perelman's work had been "thoroughly checked."^{[45]} In 2015, Abbas Bahri pointed out a counterexample to one of Morgan and Tian's theorems, which was later fixed by Morgan and Tian and sourced to an incorrectly computed evolution equation.^{[46]}^{[47]} The error, introduced by Morgan and Tian, dealt with details not directly discussed in Perelman's original work. In 2008, Morgan and Tian posted a paper which covered the details of the proof of the geometrization conjecture.^{[48]} Morgan and Tian's two articles have been published in book form by the Clay Mathematics Institute.
Fields Medal and Millennium Prize
In May 2006, a committee of nine mathematicians voted to award Perelman a Fields Medal for his work on the Ricci flow.^{[41]} However, Perelman declined to accept the prize. Sir John Ball, president of the International Mathematical Union, approached Perelman in Saint Petersburg in June 2006 to persuade him to accept the prize. After 10 hours of attempted persuasion over two days, Ball gave up. Two weeks later, Perelman summed up the conversation as follows: "He proposed to me three alternatives: accept and come; accept and don't come, and we will send you the medal later; third, I don't accept the prize. From the very beginning, I told him I have chosen the third one ... [the prize] was completely irrelevant for me. Everybody understood that if the proof is correct, then no other recognition is needed."^{[41]} "'I'm not interested in money or fame,' he is quoted to have said at the time. 'I don't want to be on display like an animal in a zoo. I'm not a hero of mathematics. I'm not even that successful; that is why I don't want to have everybody looking at me.'"^{[49]}
Nevertheless, on 22 August 2006, at the International Congress of Mathematicians in Madrid, Perelman was offered the Fields Medal "for his contributions to geometry and his revolutionary insights into the analytical and geometric structure of the Ricci flow".^{[50]} He did not attend the ceremony, and the presenter informed the congress that Perelman declines to accept the medal, which made him the only person to have ever declined the prize.^{[10]}^{[51]}
He had previously rejected a prestigious prize from the European Mathematical Society.^{[10]}
On 18 March 2010, Perelman was awarded a Millennium Prize for solving the problem.^{[52]} On 8 June 2010, he did not attend a ceremony in his honor at the Institut Océanographique, Paris to accept his $1 million prize.^{[53]} According to Interfax, Perelman refused to accept the Millennium prize in July 2010. He considered the decision of the Clay Institute unfair for not sharing the prize with Richard S. Hamilton,^{[8]} and stated that "the main reason is my disagreement with the organized mathematical community. I don't like their decisions, I consider them unjust."^{[9]}
The Clay Institute subsequently used Perelman's prize money to fund the "Poincaré Chair", a temporary position for young promising mathematicians at the Paris Institut Henri Poincaré.^{[54]}
Possible withdrawal from mathematics
Perelman quit his job at the Steklov Institute in December 2005.^{[55]} His friends are said to have stated that he currently finds mathematics a painful topic to discuss; by 2010, some even said that he had entirely abandoned mathematics.^{[56]}
Perelman is quoted in a 2006 article in The New Yorker saying that he was disappointed with the ethical standards of the field of mathematics. The article implies that Perelman refers particularly to alleged efforts of Fields medalist ShingTung Yau to downplay Perelman's role in the proof and play up the work of Cao and Zhu. Perelman added, "I can't say I'm outraged. Other people do worse. Of course, there are many mathematicians who are more or less honest. But almost all of them are conformists. They are more or less honest, but they tolerate those who are not honest."^{[41]} He also said, "It is not people who break ethical standards who are regarded as aliens. It is people like me who are isolated."^{[41]}
This, combined with the possibility of being awarded a Fields medal, led him to state he had quit professional mathematics by 2006. He said, "As long as I was not conspicuous, I had a choice. Either to make some ugly thing or, if I didn't do this kind of thing, to be treated as a pet. Now, when I become a very conspicuous person, I cannot stay a pet and say nothing. That is why I had to quit." (The New Yorker authors explained Perelman's reference to "some ugly thing" as "a fuss" on Perelman's part about the ethical breaches he perceived.)^{[57]}
It is uncertain whether his resignation from Steklov and subsequent seclusion mean that he has ceased to practice mathematics. Fellow countryman and mathematician Yakov Eliashberg said that, in 2007 Perelman confided to him that he was working on other things but it was too premature to talk about it. He is said to have been interested in the past in the Navier–Stokes equations and the problem of their solutions’ existence and smoothness.^{[58]}
In 2014, Russian media reported that Perelman was working in the field of nanotechnology in Sweden.^{[59]} However, shortly afterwards, he was spotted again in his native hometown, Saint Petersburg.^{[59]}
Perelman and the media
Perelman has avoided journalists and other members of the media. Masha Gessen, author of the mathematician's biography Perfect Rigour: A Genius and the Mathematical Breakthrough of the Century, was unable to meet him.^{[60]}
A Russian documentary about Perelman in which his work is discussed by several leading mathematicians including Mikhail Gromov was released in 2011 under the title "Иноходец. Урок Перельмана" ("Maverick: Perelman's Lesson").
In April 2011, Aleksandr Zabrovsky, producer of "PresidentFilm" studio, claimed to have held an interview with Perelman and agreed to shoot a film about him, under the tentative title The Formula of the Universe.^{[61]} Zabrovsky says that in the interview,^{[62]} Perelman explained why he rejected the one million dollar prize.^{[61]} A number of journalists^{[63]}^{[64]}^{[65]} believe that Zabrovky's interview is most likely a fake, pointing to contradictions in statements supposedly made by Perelman.
The writer Brett Forrest briefly interacted with Perelman in 2012.^{[66]}^{[67]} A reporter who had called him was told: "You are disturbing me. I am picking mushrooms."^{[68]}
Complete publication list
Dissertation
 Перельман, Григорий Яковлевич (1990). Седловые поверхности в евклидовых пространствах [Saddle surfaces in Euclidean spaces] (in Russian). Ленинградский государственный университет. Автореф. дис. на соиск. учен. степ. канд. физ.мат. наук.
{{cite book}}
: CS1 maint: postscript (link)
Research papers
P85.  Perelʹman, G. Ya. (1985). "Realization of abstract kskeletons as kskeletons of intersections of convex polyhedra in R^{2k − 1}". In Ivanov, L. D. (ed.). Geometric questions in the theory of functions and sets. Kalinin: Kalinin gosudarstvennyy universitet. pp. 129–131. MR 0829936. Zbl 0621.52003.

PP86.  Polikanova, I. V.; Perelʹman, G. Ya. (1986). "A remark on Helly's theorem". Sibirskij Matematiceskij Zurnal. 27 (5): 191–194. MR 0873724. Zbl 0615.52009.

P87.  Perelʹman, G. Ya. (1987). "kradii of a convex body". Siberian Mathematical Journal. 28 (4): 665–666. doi:10.1007/BF00973857. MR 0906047. S2CID 122265141. Zbl 0637.52009.

P88.  Perelʹman, G. Ya. (1991). "Polyhedral saddle surfaces". Journal of Soviet Mathematics. 54 (1): 735–740. doi:10.1007/BF01097421. MR 0971977. S2CID 121040191. English translation of Ukrainskiĭ Geometricheskiĭ Sbornik. 31: 100–108. 1988. Zbl 0719.53038.
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P89.  Perelʹman, G. Ya. (1992). "An example of a complete saddle surface in R^{4} with Gaussian curvature bounded away from zero". Journal of Soviet Mathematics. 59 (2): 760–762. doi:10.1007/BF01097177. MR 1049373. S2CID 121011846. English translation of Ukrainskiĭ Geometricheskiĭ Sbornik. 32: 99–102. 1989. Zbl 0741.53037.
{{cite journal}} : Missing or empty title= (help) 
BGP92.  Burago, Yu.; Gromov, M.; Perelʹman, G. (1992). "A. D. Aleksandrov spaces with curvatures bounded below". Russian Mathematical Surveys. 47 (2): 1–58. doi:10.1070/RM1992v047n02ABEH000877. MR 1185284. Zbl 0802.53018.

P93.  Perelʹman, G. Ya. (1994). "Elements of Morse theory on Aleksandrov spaces". St. Petersburg Mathematical Journal. 5 (1): 205–213. MR 1220498. English translation of Algebra i Analiz. 5 (1): 232–241. 1993. Zbl 0815.53072.
{{cite journal}} : Missing or empty title= (help) 
PP93.  Perelʹman, G. Ya.; Petrunin, A. M. (1994). "Extremal subsets in Aleksandrov spaces and the generalized Liberman theorem". St. Petersburg Mathematical Journal. 5 (1): 215–227. MR 1220499. English translation of Algebra i Analiz. 5 (1): 242–256. 1993. Zbl 0802.53019.
{{cite journal}} : Missing or empty title= (help) 
P94a.  Perelman, G. (1994). "Manifolds of positive Ricci curvature with almost maximal volume". Journal of the American Mathematical Society. 7 (2): 299–305. doi:10.1090/S08940347199412316907. MR 1231690. Zbl 0799.53050.

P94b.  Perelman, G. (1994). "Proof of the soul conjecture of Cheeger and Gromoll". Journal of Differential Geometry. 40 (1): 209–212. doi:10.4310/jdg/1214455292. MR 1285534. Zbl 0818.53056.

P95a.  Perelman, G. (1995). "Spaces with curvature bounded below" (PDF). In Chatterji, S. D. (ed.). Proceedings of the International Congress of Mathematicians, Vol. 1. Zürich, Switzerland ( 3–11 August 1994). Basel: Birkhäuser. pp. 517–525. doi:10.1007/9783034890786. ISBN 3764351535. MR 1403952. Zbl 0838.53033.

P95b.  Perelman, G. (1995). "A diameter sphere theorem for manifolds of positive Ricci curvature". Mathematische Zeitschrift. 218 (4): 595–596. doi:10.1007/BF02571925. MR 1326988. S2CID 122333596. Zbl 0831.53033.

P95c.  Perelman, G. (1995). "Widths of nonnegatively curved spaces". Geometric and Functional Analysis. 5 (2): 445–463. doi:10.1007/BF01895675. MR 1334875. S2CID 120415759. Zbl 0845.53031.

P97a.  Perelman, G. (1997). "Collapsing with no proper extremal subsets" (PDF). In Grove, Karsten; Petersen, Peter (eds.). Comparison geometry. Special Year in Differential Geometry held in Berkeley, CA, 1993–94. Mathematical Sciences Research Institute Publications. Vol. 30. Cambridge: Cambridge University Press. pp. 149–155. ISBN 0521592224. MR 1452871. Zbl 0887.53049.

P97b.  Perelman, G. (1997). "Construction of manifolds of positive Ricci curvature with big volume and large Betti numbers" (PDF). In Grove, Karsten; Petersen, Peter (eds.). Comparison geometry. Special Year in Differential Geometry held in Berkeley, CA, 1993–94. Mathematical Sciences Research Institute Publications. Vol. 30. Cambridge: Cambridge University Press. pp. 157–163. ISBN 0521592224. MR 1452872. Zbl 0890.53038.

P97c.  Perelman, G. (1997). "A complete Riemannian manifold of positive Ricci curvature with Euclidean volume growth and nonunique asymptotic cone" (PDF). In Grove, Karsten; Petersen, Peter (eds.). Comparison geometry. Special Year in Differential Geometry held in Berkeley, CA, 1993–94. Mathematical Sciences Research Institute Publications. Vol. 30. Cambridge: Cambridge University Press. pp. 165–166. ISBN 0521592224. MR 1452873. Zbl 0887.53038.

Unpublished work
P91.  Perelman, G. (1991). Alexandrov's spaces with curvatures bounded from below II (PDF) (Preprint).

PP95.  Perelman, G.; Petrunin, A. (1995). Quasigeodesics and gradient curves in Alexandrov spaces (PDF) (Preprint).

P95d.  Perelman, G. (1995). DC structure on Alexandrov space (preliminary version) (PDF) (Preprint).

P02.  Perelman, Grisha (2002). "The entropy formula for the Ricci flow and its geometric applications". arXiv:math/0211159. Zbl 1130.53001

P03a.  Perelman, Grisha (2003). "Ricci flow with surgery on threemanifolds". arXiv:math/0303109. Zbl 1130.53002

P03b.  Perelman, Grisha (2003). "Finite extinction time for the solutions to the Ricci flow on certain threemanifolds". arXiv:math/0307245. Zbl 1130.53003

See also
 Ancient solution
 Asteroid 50033 Perelman
 Homology sphere
 Hyperbolic manifold
 "Manifold Destiny" (On The New Yorker article)
 Spherical space form conjecture
 Thurston elliptization conjecture
 Uniformization theorem
Notes
 ^ "Perfect Rigour: A Genius and the Mathematical Breakthrough of the Century by Masha Gessen – review". the Guardian. 27 March 2011. Retrieved 25 July 2022.
 ^ Company, Sudo Null. "Sudo Null – Latest IT News". SudoNull. Retrieved 25 July 2022.
 ^ "Brilliant & Reclusive Russian Mathematician Doesn't Need Your Prize Money". Discover Magazine. Retrieved 25 July 2022.
 ^ "Fields Medals 2006". International Mathematical Union (IMU) – Prizes. Archived from the original on June 17, 2013. Retrieved April 30, 2006.
 ^ "Russian maths genius Perelman urged to take $1m prize". BBC News. 24 March 2010.
 ^ Dana Mackenzie (2006). "Breakthrough of the year. The Poincaré Conjecture – Proved". Science. 314 (5807): 1848–1849. doi:10.1126/science.314.5807.1848. PMID 17185565.
 ^ "The Poincaré Conjecture". Archived from the original on 5 July 2014. Retrieved 1 May 2014.
 ^ ^{a} ^{b} "Последнее "нет" доктора Перельмана". Interfax. 1 July 2010. Archived from the original on 2 July 2010. Retrieved 1 July 2010.
 ^ ^{a} ^{b} Malcolm Ritter (1 July 2010). "Russian mathematician rejects $1 million prize". AP on PhysOrg. Archived from the original on 17 January 2012. Retrieved 15 May 2011.
 ^ ^{a} ^{b} ^{c} "Maths genius declines top prize". BBC News. 22 August 2006. Archived from the original on 15 August 2010.
 ^ ^{a} ^{b} ^{c} Osborn, Andrew (27 March 2010). "Russian maths genius may turn down $1m prize". The Daily Telegraph. Archived from the original on 30 March 2010. Retrieved 2 July 2010.
He has suffered antiSemitism (he is Jewish)....Grigory is pure Jewish and I never minded that but my bosses did
 ^ McKie, Robin (27 March 2011). "Perfect Rigour: A Genius and the Mathematical Breakthrough of the Century by Masha Gessen – review". The Guardian. Archived from the original on 4 October 2013. Retrieved 23 August 2013.
Given that his parents were Jewish, Perelman, who was born in 1966, was fortunate in those who took up his cause.
 ^ Masha Gessen (2009, p. 48)
 ^ ^{a} ^{b} John Allen Paulos (29 April 2010). "He Conquered the Conjecture". The New York Review of Books.
 ^ "Eccentric 'Mathsputin' Rejects Million Dollar Prize". Fox News. Archived from the original on 15 July 2014. Retrieved 8 July 2014.
 ^ ^{a} ^{b} "International Mathematical Olympiad". Imoofficial.org. Archived from the original on 2 November 2012. Retrieved 25 December 2012.
 ^ Masha Gessen (2009, p. 45)
 ^ "Young mathematician prize of the St. Petersburg Mathematical Society".
 ^ Efimov, N. V. Generation of singularites on surfaces of negative curvature. Mat. Sb. (N.S.) 64 (106) 1964 286–320.
 ^ Smale, Stephen. Generalized Poincaré's conjecture in dimensions greater than four. Ann. of Math. (2) 74 (1961), 391–406.
 ^ Freedman, Michael Hartley. The topology of fourdimensional manifolds. J. Differential Geometry 17 (1982), no. 3, 357–453.
 ^ Thurston, William P. Threedimensional manifolds, Kleinian groups and hyperbolic geometry. Bull. Amer. Math. Soc. (N.S.) 6 (1982), no. 3, 357–381.
 ^ John Morgan. "The Poincaré conjecture." Lecture at 2006 International Congress of Mathematicians.
 ^ Hamilton, Richard S. Threemanifolds with positive Ricci curvature. J. Differential Geometry 17 (1982), no. 2, 255–306.
 ^ Hamilton, Richard S. Fourmanifolds with positive curvature operator. J. Differential Geom. 24 (1986), no. 2, 153–179.
 ^ Hamilton, Richard S. The Ricci flow on surfaces. Mathematics and general relativity (Santa Cruz, CA, 1986), 237–262, Contemp. Math., 71, Amer. Math. Soc., Providence, RI, 1988.
 ^ "Autobiography of Richard S Hamilton  the Shaw Prize".
 ^ Hamilton, Richard S. (1995). "The formation of singularities in the Ricci flow". Surveys in Differential Geometry. II: 7–136.
 ^ Hamilton, Richard S. (1997). "Fourmanifolds with positive isotropic curvature". Comm. Anal. Geom. 5 (1): 1–92. doi:10.4310/CAG.1997.v5.n1.a1.
 ^ Yau, ShingTung. Perspectives on geometric analysis. Surveys in differential geometry. Vol. X, 275–379, Surv. Differ. Geom., 10, Int. Press, Somerville, MA, 2006.
 ^ Hamilton, Richard S. Nonsingular solutions of the Ricci flow on threemanifolds. Comm. Anal. Geom. 7 (1999), no. 4, 695–729.
 ^ Colding, Tobias H.; Minicozzi, William P., II. Estimates for the extinction time for the Ricci flow on certain 3manifolds and a question of Perelman. J. Amer. Math. Soc. 18 (2005), no. 3, 561–569.
 ^ Colding, Tobias H.; Minicozzi, William P., II. Width and finite extinction time of Ricci flow. Geom. Topol. 12 (2008), no. 5, 2537–2586.
 ^ Colding, Tobias Holck; Minicozzi, William P., II. A course in minimal surfaces. Graduate Studies in Mathematics, 121. American Mathematical Society, Providence, RI, 2011. xii+313 pp. ISBN 9780821853238
 ^ Li, Peter; Yau, ShingTung. On the parabolic kernel of the Schrödinger operator. Acta Math. 156 (1986), no. 34, 153–201.
 ^ Shioya, Takashi; Yamaguchi, Takao. Volume collapsed threemanifolds with a lower curvature bound. Math. Ann. 333 (2005), no. 1, 131–155.
 ^ Morgan, John; Tian, Gang. The geometrization conjecture. Clay Mathematics Monographs, 5. American Mathematical Society, Providence, RI; Clay Mathematics Institute, Cambridge, MA, 2014. x+291 pp. ISBN 9780821852019
 ^ Cao, Jianguo; Ge, Jian. A simple proof of Perelman's collapsing theorem for 3manifolds. J. Geom. Anal. 21 (2011), no. 4, 807–869.
 ^ Kleiner, Bruce; Lott, John. Locally collapsed 3manifolds. Astérisque No. 365 (2014), 7–99. ISBN 9782856297957
 ^ Kleiner, Bruce; Lott, John (2008). "Notes on Perelman's papers". Geometry & Topology. 12 (5): 2587–2855. arXiv:math/0605667. doi:10.2140/gt.2008.12.2587. S2CID 119133773.
 ^ ^{a} ^{b} ^{c} ^{d} ^{e} ^{f} Nasar, Sylvia; Gruber, David (21 August 2006). "Manifold Destiny: A legendary problem and the battle over who solved it". The New Yorker. Archived from the original on 19 March 2011. Retrieved 21 January 2011.
 ^ Cao, HuaiDong; Zhu, XiPing (2006). "Erratum to "A complete proof of the Poincaré and geometrization conjectures – application of the Hamilton–Perelman theory of the Ricci flow", Asian J. Math., Vol. 10, No. 2, 165–492, 2006". Asian Journal of Mathematics. 10 (4): 663–664. doi:10.4310/ajm.2006.v10.n2.a2. MR 2282358.
 ^ Cao, HuaiDong; Zhu, XiPing (3 December 2006). "Hamilton–Perelman's Proof of the Poincaré Conjecture and the Geometrization Conjecture". arXiv:math.DG/0612069.
 ^ John W. Morgan, Gang Tian Ricci Flow and the Poincaré Conjecture arXiv:math/0607607
 ^ "Schedule of the scientific program of the ICM 2006". Icm2006.org. Archived from the original on 11 February 2010. Retrieved 21 March 2010.
 ^ Bahri, Abbas (2015). "Five gaps in mathematics". Adv. Nonlinear Stud. 15 (2): 289–319. doi:10.1515/ans20150202. S2CID 125566270.
 ^ Morgan, John; Tian, Gang (2015), Correction to Section 19.2 of Ricci Flow and the Poincare Conjecture, arXiv:1512.00699, Bibcode:2015arXiv151200699M.
 ^ John W. Morgan, Gang Tian Completion of the Proof of the Geometrization Conjecture arXiv:0809.4040
 ^ "Maths genius urged to take prize". BBC News. 24 March 2010. Archived from the original on 19 April 2010. Retrieved 25 March 2010.
 ^ "Fields Medal – Grigory Perelman" (PDF). International Congress of Mathematicians 2006. 22 August 2006. Archived from the original (PDF) on 3 November 2012. Retrieved 22 August 2006.
 ^ Mullins.
 ^ "Prize for Resolution of the Poincaré Conjecture Awarded to Dr. Grigoriy Perelman" (PDF) (Press release). Clay Mathematics Institute. 18 March 2010. Retrieved 1 May 2014.
The Clay Mathematics Institute (CMI) announces today that Dr. Grigoriy Perelman of St. Petersburg, Russia, is the recipient of the Millennium Prize for resolution of the Poincaré conjecture.
 ^ "Russian math genius ignores $1 million Millennium Prize". RIA Novosti. 8 July 2010. Archived from the original on 11 June 2010. Retrieved 8 July 2010.
 ^ "Poincaré Chair". Clay Institute. 4 March 2014.
 ^ Masha Gessen (2009, p. 185)
 ^ Главные новости (in Russian). RBC Information Systems. 22 August 2006. Archived from the original on 16 July 2011. Retrieved 21 March 2010.
 ^ Nasar, Sylvia; Gruber, David (21 August 2006). "Manifold Destiny: A legendary problem and the battle over who solved it". The New Yorker. p. 11. Archived from the original on 18 October 2012. Retrieved 21 January 2011.
 ^ "Le génie qui s'est retiré du monde" [The genius who has withdrawn from the world]. Le Point (in French). 30 September 2010. pp. 74–77. Archived from the original on 21 July 2012. Retrieved 15 October 2010.
 ^ ^{a} ^{b} "Komsomolskaya Pravda" found out where Perelman disappears ANNA VELIGZHANINA
 ^ Nikolai Gerasimov (27 March 2011). Чтобы купить русского хлеба, Перельман пешком ходил через весь НьюЙорк [To buy Russian bread, Perelman walked through the whole New York]. Komsomolskaya Pravda (in Russian). Archived from the original on 17 September 2012. Retrieved 25 December 2012.
 ^ ^{a} ^{b} Anna Veligzhanina (28 April 2011). Интервью с математиком Григорием Перельманом: Зачем мне миллион долларов? Я могу управлять Вселенной [Interview with mathematician Grigori Perelman: Why do I need million dollars? I can control the world]. Komsomolskaya Pravda (in Russian). Archived from the original on 27 December 2012. Retrieved 25 December 2012.
 ^ "Russian math genius answers $1 million question". RIA Novosti. 29 April 2011. Retrieved 25 December 2012.
 ^ Masha Gessen (29 April 2011). "6 странных ошибок в "интервью Перельмана"". Snob.ru. Archived from the original on 17 October 2012. Retrieved 8 May 2012.
 ^ "Интервью Перельмана – подделка?" [Interview with Perelman – fake?]. Versii. 5 May 2011. Archived from the original on 26 December 2012. Retrieved 25 December 2012.
 ^ "Grigori Perelman's interview full of mismatches". English Pravda.ru. 5 June 2011. Archived from the original on 22 January 2013. Retrieved 25 December 2012.
 ^ "Articles » Shattered Genius". Brett Forrest. Retrieved 25 December 2012.
 ^ "Seven of the week's best reads". BBC News. 1 September 2012. Archived from the original on 8 March 2013. Retrieved 25 December 2012.
 ^ Luke Harding (23 March 2010). "Grigory Perelman, the maths genius who said no to $1m". The Guardian.
References
 Anderson, M.T. 2005. Singularities of the Ricci flow. Encyclopedia of Mathematical Physics, Elsevier.
 The Associated Press, "Russian may have solved great math mystery". CNN. 1 July 2004. Archived from the original on 13 August 2006. Retrieved 15 August 2006.
 Cao, HuaiDong; Zhu, XiPing (June 2006). "A Complete Proof of the Poincaré and Geometrization Conjectures – application of the HamiltonPerelman theory of the Ricci flow" (PDF). Asian Journal of Mathematics. 10 (2). Archived from the original (PDF) on 14 May 2012. Erratum. Revised version (December 2006): HamiltonPerelman's Proof of the Poincaré Conjecture and the Geometrization Conjecture
 Collins, Graham P. (2004). "The Shapes of Space". Scientific American. 291 (July): 94–103. Bibcode:2004SciAm.291a..94C. doi:10.1038/scientificamerican070494. PMID 15255593.
 Gessen, Masha (2009). Perfect Rigor: A Genius and the Mathematical Breakthrough of the Century. Boston, Massachusetts: Houghton Mifflin Harcourt. ISBN 9780151014064.
 Jackson, Allyn (September 2006). "Conjectures No More? Consensus Forming on the Proof of the Poincaré and Geometrization Conjectures" (PDF). Notices of the AMS.
 Kleiner, Bruce; Lott, John (2008). "Notes on Perelman's papers". Geometry & Topology. 12 (5): 2587–2855. arXiv:math.DG/0605667. doi:10.2140/gt.2008.12.2587. S2CID 119133773.
 Kusner, Rob. "Witnesses to Mathematical History Ricci Flow and Geometry" (PDF). Retrieved 22 August 2006. (an account of Perelman's talk on his proof at MIT; pdf file; also see Sugaku Seminar 2003–10 pp 4–7 for an extended version in Japanese)
 Lobastova, Nadejda; Hirst, Michael (20 August 2006). "World's top maths genius jobless and living with mother". The Daily Telegraph. Archived from the original on 8 June 2014. Retrieved 10 May 2014.
 Morgan, John W.; Gang Tian (25 July 2006). "Ricci Flow and the Poincaré Conjecture". arXiv:math.DG/0607607.
 Mullins, Justin (22 August 2006). "Prestigious Fields Medals for mathematics awarded". New Scientist.
 Overbye, Dennis (15 August 2006). "An Elusive Proof and Its Elusive Prover". The New York Times. Retrieved 15 August 2006.
 Randerson, James (16 August 2006). "Meet the cleverest man in the world (who's going to say no to a $1m prize)". The Guardian. London.
 Robinson, Sara (15 April 2003). "Russian Reports He Has Solved a Celebrated Math Problem". The New York Times. Retrieved 20 August 2006.
 Schecter, Bruce (17 July 2004). "Taming the fourth dimension". New Scientist. 183 (2456).
 Weeks, Jeffrey R. (2002). The Shape of Space. New York: Marcel Dekker. ISBN 0824707095. (The author is a former PhD student of Bill Thurston.)
 Weisstein, Eric (15 April 2004). "Poincaré Conjecture Proved – This Time for Real". Mathworld. Retrieved 22 August 2006.
Further reading
 Gessen, Masha (2009). Perfect Rigor: A Genius and the Mathematical Breakthrough of the Century. Houghton Mifflin Harcourt. ISBN 9780151014064. Retrieved 12 December 2012. (Story of Grigory Perelman based on information from people who interacted with him.)
External links
 Grigori Perelman at the Mathematics Genealogy Project
 Grigori Perelman's results at International Mathematical Olympiad
 O'Connor, John J.; Robertson, Edmund F., "Grigori Perelman", MacTutor History of Mathematics archive, University of St Andrews