sign in sign up
<<
Home , Alexander Beilinson, Alexandre Kirillov, Claire Voisin, David Kazhdan, George Lusztig, Henryk Iwaniec

COMMUNICATION

Beilinson and Kazhdan Awarded 2020

The Shaw Foundation has announced the awarding of the 2020 Shaw Prize to of the and of the Hebrew University of Jerusalem “for their huge influence on and profound contributions to , as well as many other areas of .”

for example, they describe how the symmetry group of a physical system affects the solutions of equations describing that system, and the representations also make the symme- try group better understood. In loose terms, representation theory is the study of the basic symmetries of mathematics and physics. Symmetry groups are of many different kinds: finite groups, Lie groups, algebraic groups, p-adic groups, loop groups, adelic groups. This may partly explain how Beilinson and Kazhdan have been able to contribute to so many different fields. One of Kazhdan’s most influential ideas has been the introduction of a property of groups that is known as Alexander Beilinson David Kazhdan Kazhdan’s property (T). Among the representations of a group there is always the not very interesting “trivial rep- Citation for Beilinson and Kazhdan resentation,” where we associate with each group element Alexander Beilinson and David Kazhdan are two mathe- the “transformation” that does nothing at all to the object. maticians who have made profound contributions to the While the trivial representation is not interesting on its branch of mathematics known as representation theory but own, much more interesting is the question of how close who are also famous for the fundamental influence they another representation can be to the trivial one. Property have had on many other areas, such as arithmetic , (T) gives a precise quantitative meaning to this question. Kazhdan used Property (T) to solve two outstanding ques- K-theory, conformal field theory, , algebraic tions about discrete subgroups of Lie groups. Since then it and complex geometry, group theory, and more has had important applications to group representation generally. As well as proving remarkable theorems them- theory, lattices in algebraic groups over local fields, ergodic selves, they have created conceptual tools that have been theory, geometric group theory, expanders, operator alge- essential to many breakthroughs of other . bras and the theory of networks, and has been recognized Thanks to their work and its exceptionally broad reach, as a truly fundamental concept in representation theory. large are significantly more advanced After this first breakthrough, Kazhdan solved several than they would otherwise have been. other outstanding problems about lattices in Lie groups Group theory is intimately related to the notion of sym- and representation theory, such as the Selberg conjecture metry, and one can think of a representation of a group as about nonuniform lattices and the Springer conjecture on a “description” of it as a group of transformations, or sym- the classification of affine Hecke . metries, of some mathematical object, usually linear trans- While working with on this last problem, formations of a vector space. Representations of groups are Kazhdan introduced an important family of polynomials, important, as they allow many group-theoretic problems as well as formulating a very influential pair of (equivalent) to be reduced to problems in , which is well conjectures. One of Alexander Beilinson’s achievements understood. They are also important in physics because, was to prove these conjectures with . (They

1252 Notices of the American Mathematical Society Volume 67, Number 8 COMMUNICATION were also proved independently by Jean-Luc Brylinski and University under the direction of . He .) The methods introduced in this proof left the in 1975 to take a position at Harvard led to the area known as geometric representation theory, University, where he is now professor emeritus. He moved an area that Kazhdan also played an important part in de- to in 2002. He received the Rothschild Prize in 2010; veloping, which aims to understand the deeper geometric the Israel Prize, the country’s highest honor, in 2012; and and categorical structures that often underlie group repre- the EMET Prize in Exact Sciences (with Joseph Bernstein) sentations. The resulting insights have been used to solve in 2016. He was a MacArthur Fellow from 1990 to 1995. several open problems. He was doctoral advisor to , who won Another famous concept, this one established by Beil- the in 2002. Kazhdan is a member of the US inson, Bernstein, and , is that of a perverse National Academy of Sciences, the American Academy of . It is not feasible to give a nontechnical explanation Arts and Sciences, and the Israel Academy of Sciences. of what a is—one well-known account begins About the Prize by helpfully stating that it is neither perverse nor a sheaf— The Shaw Prize is an international award established to but it is another concept that can be described as a true honor individuals who are currently active in their respec- discovery, in that it has a far from obvious definition, but it tive fields and who have achieved distinguished and signif- is now seen to be “one of the most natural and fundamental icant advances, who have made outstanding contributions objects in ” (to quote from the same account). One in culture and the arts, or who have achieved excellence in of the central goals of mathematics, the , other domains. The award is dedicated to furthering societal has been deeply influenced by this concept. For example, progress, enhancing quality of life, and enriching humani- the whole work of Ngô on the “fundamental lemma” and ty’s spiritual civilization. Preference is given to individuals the contributions of Laurent and Vincent Lafforgue (all whose significant work was recently achieved. three of them major prizewinners for this work) would The Shaw Prize consists of three annual awards: the have been unthinkable without it. Kazhdan too has brought Prize in , the Prize in Science and , and extraordinary mathematical insight into this circle of ideas. the Prize in Mathematical Sciences. Established under the By pointing out that orbital integrals could be interpreted auspices of Run Run Shaw in November 2002, the prize is as counting points on certain algebraic varieties over finite managed and administered by the Shaw Prize Foundation fields, he and Lusztig opened the way to the proof of the based in . The prize carries a cash award of fundamental lemma, and since then Kazhdan has had and US$1,200,000. continues to have an enormous influence on the subject. Previous recipients of the Shaw Prize in Mathematical Beilinson is also famous for formulating deep conjectures Sciences are: relating L-functions and motivic theory, which have com- •• (2019) pletely changed the understanding of both topics and led •• (2018) to an explosion of related work. •• János Kollár and (2017) Beilinson and Kazhdan are at the heart of many of the •• Nigel J. Hitchin (2016) most exciting developments in mathematics over the last •• and (2015) few decades, developments that continue to this day. It •• George Lusztig (2014) is for this that they are awarded the 2020 Shaw Prize in •• David L. Donoho (2013) Mathematical Sciences. •• (2012) Biographical Sketches •• and Richard S. Hamil- Alexander Beilinson was born in 1957 in Moscow and ton (2011) • received his PhD in 1988 from the Landau Institute of The- • (2010) •• Simon K. Donaldson and Clifford H. Taubes oretical Physics, advised by . He was a researcher (2009) at the Landau Institute from 1987 to 1993 and professor of •• and Ludwig Faddeev (2008) mathematics at the Massachusetts Institute of Technology •• and Richard Taylor (2007) from 1988 to 1998, when he joined the University of Chi- •• and Wen-Tsun Wu (2006) cago. His research interests, along with representation the- •• (2005) ory, include and . •• Shiing-Shen Chern (2004) He was awarded the Moscow Mathematical Society Prize in 1985, the Ostrowski Prize (with ) in 1999, —Shaw Foundation announcement and the Wolf Prize (with ) in 2018. He Credits is a member of the US National Academy of Sciences and Photo of Alexander Beilinson is courtesy of the University of the American Academy of Arts and Sciences. Chicago. David Kazhdan was born in Moscow in 1946. He Photo of David Kazhdan is courtesy of the Hebrew University received a Kandidat Degree in 1969 from Moscow State of Jerusalem.

September 2020 Notices of the American Mathematical Society 1253