David Mumford

David Bryant Mumford (born 11 June 1937) is an American mathematician known for distinguished work in algebraic geometry, and then for research into vision and pattern theory. He won the Fields Medal and was a MacArthur Fellow. In 2010 he was awarded the National Medal of Science. He is currently a University Professor Emeritus in the Division of Applied Mathematics at Brown University.

David Mumford
David Mumford
David Mumford in 2010
Born11 June 1937 (age 81)
NationalityAmerican
Alma materHarvard University
Known forAlgebraic geometry
Mumford surface
Mumford–Shah functional[1]
AwardsPutnam Fellow (1955, 1956)
Sloan Fellowship (1962)
Fields Medal (1974)
MacArthur Fellowship (1987)
Shaw Prize (2006)
Steele Prize (2007)
Wolf Prize (2008)
Longuet-Higgins Prize (2005, 2009)
National Medal of Science (2010)
BBVA Foundation Frontiers of Knowledge Award (2012)
Scientific career
FieldsMathematics
InstitutionsBrown University
Harvard University
Doctoral advisorOscar Zariski
Doctoral studentsAvner Ash
Henri Gillet
Tadao Oda
Emma Previato
Malka Schaps
Jonathan Wahl

Early life

Mumford was born in Worth, West Sussex in England, of an English father and American mother. His father William started an experimental school in Tanzania and worked for the then newly created United Nations.[2]

In high school, he was a finalist in the prestigious Westinghouse Science Talent Search. After attending the Phillips Exeter Academy, Mumford went to Harvard, where he became a student of Oscar Zariski. At Harvard, he became a Putnam Fellow in 1955 and 1956. He completed his Ph.D. in 1961, with a thesis entitled Existence of the moduli scheme for curves of any genus.

Work in algebraic geometry

Mumford's work in geometry combined traditional geometric insights with the latest algebraic techniques. He published on moduli spaces, with a theory summed up in his book Geometric Invariant Theory, on the equations defining an abelian variety, and on algebraic surfaces.

His books Abelian Varieties (with C. P. Ramanujam) and Curves on an Algebraic Surface combined the old and new theories. His lecture notes on scheme theory circulated for years in unpublished form, at a time when they were, beside the treatise Éléments de géométrie algébrique, the only accessible introduction. They are now available as The Red Book of Varieties and Schemes (ISBN 3-540-63293-X).

Other work that was less thoroughly written up were lectures on varieties defined by quadrics, and a study of Goro Shimura's papers from the 1960s.

Mumford's research did much to revive the classical theory of theta functions, by showing that its algebraic content was large, and enough to support the main parts of the theory by reference to finite analogues of the Heisenberg group. This work on the equations defining abelian varieties appeared in 1966–7. He published some further books of lectures on the theory.

He also was one of the founders of the toroidal embedding theory; and sought to apply the theory to Gröbner basis techniques, through students who worked in algebraic computation.

Work on pathologies in algebraic geometry

In a sequence of four papers published in the American Journal of Mathematics between 1961 and 1975, Mumford explored pathological behavior in algebraic geometry, that is, phenomena that would not arise if the world of algebraic geometry were as well-behaved as one might expect from looking at the simplest examples. These pathologies fall into two types: (a) bad behavior in characteristic p and (b) bad behavior in moduli spaces.

Characteristic-p pathologies

Mumford's philosophy in characteristic p was as follows:

A nonsingular characteristic p variety is analogous to a general non-Kähler complex manifold; in particular, a projective embedding of such a variety is not as strong as a Kähler metric on a complex manifold, and the Hodge–Lefschetz–Dolbeault theorems on sheaf cohomology break down in every possible way.

In the first Pathologies paper, Mumford finds an everywhere regular differential form on a smooth projective surface that is not closed, and shows that Hodge symmetry fails for classical Enriques surfaces in characteristic two. This second example is developed further in Mumford's third paper on classification of surfaces in characteristic p (written in collaboration with E. Bombieri). This pathology can now be explained in terms of the Picard scheme of the surface, and in particular, its failure to be a reduced scheme, which is a theme developed in Mumford's book "Lectures on Curves on an Algebraic Surface". Worse pathologies related to p-torsion in crystalline cohomology were explored by Luc Illusie (Ann. Sci. Ec. Norm. Sup. (4) 12 (1979), 501–661).

In the second Pathologies paper, Mumford gives a simple example of a surface in characteristic p where the geometric genus is non-zero, but the second Betti number is equal to the rank of the Néron–Severi group. Further such examples arise in Zariski surface theory. He also conjectures that the Kodaira vanishing theorem is false for surfaces in characteristic p. In the third paper, he gives an example of a normal surface for which Kodaira vanishing fails. The first example of a smooth surface for which Kodaira vanishing fails was given by Michel Raynaud in 1978.

Pathologies of moduli spaces

In the second Pathologies paper, Mumford finds that the Hilbert scheme parametrizing space curves of degree 14 and genus 24 has a multiple component. In the fourth Pathologies paper, he finds reduced and irreducible complete curves which are not specializations of non-singular curves.

These sorts of pathologies were considered to be fairly scarce when they first appeared. But recently, Ravi Vakil in a paper called "Murphy's law in algebraic geometry" has shown that Hilbert schemes of nice geometric objects can be arbitrarily "bad", with unlimited numbers of components and with arbitrarily large multiplicities (Invent. Math. 164 (2006), 569–590).

Classification of surfaces

In three papers written between 1969 and 1976 (the last two in collaboration with Enrico Bombieri), Mumford extended the Enriques–Kodaira classification of smooth projective surfaces from the case of the complex ground field to the case of an algebraically closed ground field of characteristic p. The final answer turns out to be essentially as the answer in the complex case (though the methods employed are sometimes quite different), once two important adjustments are made. The first is that one may get "non-classical" surfaces, which come about when p-torsion in the Picard scheme degenerates to a non-reduced group scheme. The second is the possibility of obtaining quasi-elliptic surfaces in characteristics two and three. These are surfaces fibred over a curve where the general fibre is a curve of arithmetic genus one with a cusp.

Once these adjustments are made, the surfaces are divided into four classes by their Kodaira dimension, as in the complex case. The four classes are: a) Kodaira dimension minus infinity. These are the ruled surfaces. b) Kodaira dimension 0. These are the K3 surfaces, abelian surfaces, hyperelliptic and quasi-hyperelliptic surfaces, and Enriques surfaces. There are classical and non-classical examples in the last two Kodaira dimension zero cases. c) Kodaira dimension 1. These are the elliptic and quasi-elliptic surfaces not contained in the last two groups. d) Kodaira dimension 2. These are the surfaces of general type.

Awards and honors

Mumford2
David Mumford in 1975

Mumford was awarded a Fields Medal in 1974. He was a MacArthur Fellow from 1987 to 1992. He won the Shaw Prize in 2006. In 2007 he was awarded the Steele Prize for Mathematical Exposition by the American Mathematical Society. In 2008 he was awarded the Wolf Prize; on receiving the prize in Jerusalem from Shimon Peres, Mumford announced that he was donating half of the prize money to Birzeit University in the Palestinian territories and half to Gisha, an Israeli organization that promotes the right to freedom of movement of Palestinians in the Gaza Strip.[3][4] In 2010 he was awarded the National Medal of Science.[5] In 2012 he became a fellow of the American Mathematical Society.[6]

There is a long list of awards and honors besides the above, including

He was elected President of the International Mathematical Union in 1995 and served from 1995 to 1999.

See also

Notes

  1. ^ Mumford, David; Shah, Jayant (1989). "Optimal Approximations by Piecewise Smooth Functions and Associated Variational Problems" (PDF). Comm. Pure Appl. Math. XLII: 577–685. doi:10.1002/cpa.3160420503.
  2. ^ Fields Medallists' Lectures, World Scientific Series in 20th Century Mathematics, Vol 5. World Scientific. 1997. p. 225. ISBN 978-9810231170.
  3. ^ "U.S. prof. gives Israeli prize money to Palestinian university – Haaretz – Israel News". Haaretz. 2008-05-26. Retrieved 2008-05-26.
  4. ^ Mumford, David (September 2008). "The Wolf Prize and Supporting Palestinian Education" (PDF). Notices of the American Mathematical Society. American Mathematical Society. 55 (8): 919. ISSN 0002-9920.
  5. ^ "Mathematician David Mumford to receive National Medal of Science". Brown University. 2010-10-15. Retrieved 2010-10-25.
  6. ^ List of Fellows of the American Mathematical Society, retrieved 2013-02-10.
  7. ^ NTNU's list of honorary doctors
  8. ^ "Gruppe 1: Matematiske fag" (in Norwegian). Norwegian Academy of Science and Letters. Archived from the original on 10 November 2013. Retrieved 7 October 2010.
  9. ^ http://www.browndailyherald.com/commencement-2011-honorary-degrees-1.2579444

Publications

  • Lectures on Curves on Algebraic Surfaces (with George Bergman), Princeton University Press, 1964.
  • Geometric Invariant Theory, Springer-Verlag, 1965 – 2nd edition, with J. Fogarty, 1982; 3rd enlarged edition, with F. Kirwan and J. Fogarty, 1994.
  • Mumford, David (1999) [1967], The red book of varieties and schemes, Lecture Notes in Mathematics, 1358 (expanded, Includes Michigan Lectures (1974) on Curves and their Jacobians ed.), Berlin, New York: Springer-Verlag, doi:10.1007/b62130, ISBN 978-3-540-63293-1, MR 1748380
  • Abelian Varieties, Oxford University Press, 1st edition 1970; 2nd edition 1974.
  • Six Appendices to Algebraic Surfaces by Oscar Zariski – 2nd edition, Springer-Verlag, 1971.
  • Toroidal Embeddings I (with G. Kempf, F. Knudsen and B. Saint-Donat), Lecture Notes in Mathematics #339, Springer-Verlag 1973.
  • Curves and their Jacobians , University of Michigan Press, 1975.
  • Smooth Compactification of Locally Symmetric Varieties (with A. Ash, M. Rapoport and Y. Tai, Math. Sci. Press, 1975)
  • Algebraic Geometry I: Complex Projective Varieties , Springer-Verlag New York, 1975.
  • Tata Lectures on Theta (with C. Musili, M. Nori, P. Norman, E. Previato and M. Stillman), Birkhäuser-Boston, Part I 1982, Part II 1983, Part III 1991.
  • Filtering, Segmentation and Depth (with M. Nitzberg and T. Shiota), Lecture Notes in Computer Science #662, 1993.
  • Two and Three Dimensional Pattern of the Face (with P. Giblin, G. Gordon, P. Hallinan and A. Yuille), AKPeters, 1999.
  • Mumford, David; Series, Caroline; Wright, David (2002), Indra's Pearls: The Vision of Felix Klein, Cambridge University Press, doi:10.1017/CBO9781107050051.024, ISBN 978-0-521-35253-6, MR 1913879 Indra's Pearls: The Vision of Felix Klein
  • Selected Papers on the Classification of Varieties and Moduli Spaces, Springer-Verlag, 2004.
  • Mumford, David (2010), Selected papers, Volume II. On algebraic geometry, including correspondence with Grothendieck, New York: Springer, ISBN 978-0-387-72491-1, MR 2741810
  • Mumford, David; Desolneux, Agnès (2010), Pattern Theory: The Stochastic Analysis of Real-World Signals, A K Peters/CRC Press, ISBN 978-1568815794, MR 2723182
  • Mumford, David; Oda, Tadao (2015), Algebraic geometry. II., Texts and Readings in Mathematics, 73, New Delhi: Hindustan Book Agency, ISBN 978-93-80250-80-9, MR 3443857

External links

Alexander Grothendieck

Alexander Grothendieck (; German: [ˈɡroːtn̩diːk]; French: [ɡʁɔtɛndik]; 28 March 1928 – 13 November 2014) was a stateless mathematician (naturalized French in 1971) who became the leading figure in the creation of modern algebraic geometry. His research extended the scope of the field and added elements of commutative algebra, homological algebra, sheaf theory and category theory to its foundations, while his so-called "relative" perspective led to revolutionary advances in many areas of pure mathematics. He is considered by many to be the greatest mathematician of the 20th century.Born in Germany, Grothendieck was raised and lived primarily in France. For much of his working life, however, he was, in effect, stateless. As he consistently spelled his first name "Alexander" rather than "Alexandre" and his surname, taken from his mother, was the Dutch-like Low German "Grothendieck", he was sometimes mistakenly believed to be of Dutch origin.Grothendieck began his productive and public career as a mathematician in 1949. In 1958, he was appointed a research professor at the Institut des hautes études scientifiques (IHÉS) and remained there until 1970, when, driven by personal and political convictions, he left following a dispute over military funding. He later became professor at the University of Montpellier and, while still producing relevant mathematical work, he withdrew from the mathematical community and devoted himself to political causes. Soon after his formal retirement in 1988, he moved to the Pyrenees, where he lived in isolation until his death in 2014.

C. P. Ramanujam

Chakravarthi Padmanabhan Ramanujam (9 January 1938 – 27 October 1974) was an Indian mathematician who worked in the fields of number theory and algebraic geometry. He was elected a fellow of the Indian Academy of Sciences in 1973.

Like his namesake Srinivasa Ramanujan, Ramanujam also had a very short life.As David Mumford put it, Ramanujam felt that the spirit of mathematics demanded of him not merely routine developments but the right theorem on any given topic. "He wanted mathematics to be beautiful and to be clear and simple. He was sometimes tormented by the difficulty of these high standards, but in retrospect, it is clear to us how often he succeeded in adding to our knowledge, results both new, beautiful and with a genuinely original stamp".

David Mumford (priest)

David Christopher Mumford was Dean of Brechin from 2008 until 2012.He was born on 14 January 1947, educated at Merton College, Oxford and ordained in 1987. After curacies in Shiremoor and North Shields he was Vicar of Byker then Cowgate. He was Co-ordinator of the International Fellowship of Reconciliation from 2002 until 2007, since when he has been the Rector of Brechin.

Deligne–Mumford stack

In algebraic geometry, a Deligne–Mumford stack is a stack F such that

Pierre Deligne and David Mumford introduced this notion in 1969 when they proved that moduli spaces of stable curves of fixed arithmetic genus are proper smooth Deligne–Mumford stacks.

If the "étale" is weakened to "smooth", then such a stack is called an algebraic stack (also called an Artin stack, after Michael Artin). An algebraic space is Deligne–Mumford.

A key fact about a Deligne–Mumford stack F is that any X in , where B is quasi-compact, has only finitely many automorphisms. A Deligne–Mumford stack admits a presentation by a groupoid; see groupoid scheme.

Enriques–Kodaira classification

In mathematics, the Enriques–Kodaira classification is a classification of compact complex surfaces into ten classes. For each of these classes, the surfaces in the class can be parametrized by a moduli space. For most of the classes the moduli spaces are well understood, but for the class of surfaces of general type the moduli spaces seem too complicated to describe explicitly, though some components are known.

Max Noether began the systematic study of algebraic surfaces, and Guido Castelnuovo proved important parts of the classification. Federigo Enriques (1914, 1949) described the classification of complex projective surfaces. Kunihiko Kodaira (1964, 1966, 1968, 1968b) later extended the classification to include non-algebraic compact surfaces. The analogous classification of surfaces in positive characteristic was begun by David Mumford (1969) and completed by Enrico Bombieri and David Mumford (1976, 1977); it is similar to the characteristic 0 projective case, except that one also gets singular and supersingular Enriques surfaces in characteristic 2, and quasi-hyperelliptic surfaces in characteristics 2 and 3.

Equations defining abelian varieties

In mathematics, the concept of abelian variety is the higher-dimensional generalization of the elliptic curve. The equations defining abelian varieties are a topic of study because every abelian variety is a projective variety. In dimension d ≥ 2, however, it is no longer as straightforward to discuss such equations.

There is a large classical literature on this question, which in a reformulation is, for complex algebraic geometry, a question of describing relations between theta functions. The modern geometric treatment now refers to some basic papers of David Mumford, from 1966 to 1967, which reformulated that theory in terms from abstract algebraic geometry valid over general fields.

Hilbert–Mumford criterion

In mathematics, the Hilbert–Mumford criterion, introduced by David Hilbert and David Mumford, characterizes the semistable and stable points of a group action on a vector space in terms of eigenvalues of 1-parameter subgroups (Dieudonné & Carrell 1970, 1971, p.58).

Horrocks–Mumford bundle

In algebraic geometry, the Horrocks–Mumford bundle is an indecomposable rank 2 vector bundle on 4-dimensional projective space P4 introduced by Geoffrey Horrocks and David Mumford (1973). It is the only such bundle known, although a generalized construction involving Paley graphs produces other rank 2 sheaves (Sasukara et al. 1993). The zero sets of sections of the Horrocks–Mumford bundle are abelian surfaces of degree 10, called Horrocks–Mumford surfaces.

By computing Chern classes one sees that the second exterior power of the Horrocks–Mumford bundle F is the line bundle O(5) on P4. Therefore, the zero set V of a general section of this bundle is a quintic threefold called a Horrocks–Mumford quintic. Such a V has exactly 100 nodes; there exists a small resolution V′ which is a Calabi–Yau threefold fibered by Horrocks–Mumford surfaces.

Indra's Pearls (book)

Indra's Pearls: The Vision of Felix Klein is a geometry book written by David Mumford, Caroline Series and David Wright, and published by Cambridge University Press in 2002 and 2015.

The book explores the patterns created by iterating conformal maps of the complex plane called Möbius transformations, and their connections with symmetry and self-similarity. These patterns were glimpsed by German mathematician Felix Klein, but modern computer graphics allows them to be fully visualised and explored in detail.

Jonathan Wahl

Jonathan Wahl is a mathematician based at the University of North Carolina at Chapel Hill.Wahl received his Ph.D. from Harvard University in 1971 under the supervision of David Mumford. He earned a B.S. from Yale University in 1965 and M.A. from Yale in 1965.In 2012, Wahl became a fellow of the American Mathematical Society.

List of Fellows of the Royal Society elected in 2008

Fellows, Foreign Members and Honorary Fellows of the Royal Society elected in 2008.

Mahler's compactness theorem

In mathematics, Mahler's compactness theorem, proved by Kurt Mahler (1946), is a foundational result on lattices in Euclidean space, characterising sets of lattices that are 'bounded' in a certain definite sense. Looked at another way, it explains the ways in which a lattice could degenerate (go off to infinity) in a sequence of lattices. In intuitive terms it says that this is possible in just two ways: becoming coarse-grained with a fundamental domain that has ever larger volume; or containing shorter and shorter vectors. It is also called his selection theorem, following an older convention used in naming compactness theorems, because they were formulated in terms of sequential compactness (the possibility of selecting a convergent subsequence).

Let X be the space

that parametrises lattices in , with its quotient topology. There is a well-defined function Δ on X, which is the absolute value of the determinant of a matrix – this is constant on the cosets, since an invertible integer matrix has determinant 1 or −1.

Mahler's compactness theorem states that a subset Y of X is relatively compact if and only if Δ is bounded on Y, and there is a neighbourhood N of {0} in such that for all Λ in Y, the only lattice point of Λ in N is 0 itself.

The assertion of Mahler's theorem is equivalent to the compactness of the space of unit-covolume lattices in whose systole is larger or equal than any fixed .

Mahler's compactness theorem was generalized to semisimple Lie groups by David Mumford; see Mumford's compactness theorem.

Mumford's compactness theorem

In mathematics, Mumford's compactness theorem states that the space of compact Riemann surfaces of fixed genus g > 1 with no closed geodesics of length less than some fixed ε > 0 in the Poincaré metric is compact. It was proved by David Mumford (1971) as a consequence of a theorem about the compactness of sets of discrete subgroups of semisimple Lie groups generalizing Mahler's compactness theorem.

Mumford measure

In mathematics, a Mumford measure is a measure on a supermanifold constructed from a bundle of relative dimension 1|1. It is named for David Mumford.

Prym variety

In mathematics, the Prym variety construction (named for Friedrich Prym) is a method in algebraic geometry of making an abelian variety from a morphism of algebraic curves. In its original form, it was applied to an unramified double covering of a Riemann surface, and was used by F. Schottky and H. W. E. Jung in relation with the Schottky problem, as it is now called, of characterising Jacobian varieties among abelian varieties. It is said to have appeared first in the late work of Riemann, and was extensively studied by Wirtinger in 1895, including degenerate cases.

Given a non-constant morphism

φ: C1 → C2of algebraic curves, write Ji for the Jacobian variety of Ci. Then from φ construct the corresponding morphism

ψ: J1 → J2,which can be defined on a divisor class D of degree zero by applying φ to each point of the divisor. This is a well-defined morphism, often called the norm homomorphism. Then the Prym variety of φ is the kernel of ψ. To qualify that somewhat, to get an abelian variety, the connected component of the identity of the reduced scheme underlying the kernel may be intended. Or in other words take the largest abelian subvariety of J1 on which ψ is trivial.

The theory of Prym varieties was dormant for a long time, until revived by David Mumford around 1970. It now plays a substantial role in some contemporary theories, for example of the Kadomtsev–Petviashvili equation. One advantage of the method is that it allows one to apply the theory of curves to the study of a wider class of abelian varieties than Jacobians. For example, principally polarized abelian varieties (p.p.a.v.'s) of dimension > 3 are not generally Jacobians, but all p.p.a.v.'s of dimension 5 or less are Prym varieties. It is for this reason that p.p.a.v.'s are fairly well understood up to dimension 5.

Robin Hartshorne

Robin Cope Hartshorne (born March 15, 1938) is an American mathematician. Hartshorne is an algebraic geometer who studied with Oscar Zariski, David Mumford, Jean-Pierre Serre and Alexander Grothendieck.

He was a Putnam Fellow in Fall, 1958. He received his doctorate from Princeton University in 1963 and then became a Junior Fellow at Harvard University, where he taught for several years. In the 1970s he was appointed to the faculty at the University of California, Berkeley. He is currently retired.

Hartshorne is the author of the text Algebraic Geometry.

In 2012 he became a fellow of the American Mathematical Society.

Stable vector bundle

In mathematics, a stable vector bundle is a (holomorphic or algebraic) vector bundle that is stable in the sense of geometric invariant theory. Any holomorphic vector bundle may be built from stable ones using Harder-Narasimhan filtration. Stable bundles were defined by David Mumford in Mumford (1963) and later built upon by David Gieseker, Fedor Bogomolov, Thomas Bridgeland and many others.

Theta representation

In mathematics, the theta representation is a particular representation of the Heisenberg group of quantum mechanics. It gains its name from the fact that the Jacobi theta function is invariant under the action of a discrete subgroup of the Heisenberg group. The representation was popularized by David Mumford.

Walt's Time

Walt's Time: from before to beyond is a 252-page autobiographical, full-color book by Robert B. Sherman and Richard M. Sherman. It was edited by Disney Imagineers Bruce Gordon, David Mumford and Jeff Kurtti and was published in 1998 by Camphor Tree Publishers of Santa Clarita, California. Bruce Gordon did the book design and layout.

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.