Lê Dũng Tráng, (born 1947 in

Saigon Ho Chi Minh City (HCMC) ('','' TP.HCM; ), commonly known as Saigon (; ), is the most populous city in Vietnam with a population of around 14 million in 2025. The city's geography is defined by rivers and canals, of which the largest is Saigo ...

) is a

Vietnamese Vietnamese may refer to: * Something of, from, or related to Vietnam, a country in Southeast Asia * Vietnamese people, or Kinh people, a Southeast Asian ethnic group native to Vietnam ** Overseas Vietnamese, Vietnamese people living outside Vietna ...

- French

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

Life and work

At the end 1949, Lê Dũng Tráng came to

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

. He attended the

Lycée Louis-le-Grand The Lycée Louis-le-Grand (), also referred to simply as Louis-le-Grand or by its acronym LLG, is a public Lycée (French secondary school, also known as sixth form college) located on Rue Saint-Jacques (Paris), rue Saint-Jacques in central Par ...

Paris Paris () is the Capital city, capital and List of communes in France with over 20,000 inhabitants, largest city of France. With an estimated population of 2,048,472 residents in January 2025 in an area of more than , Paris is the List of ci ...

. He obtained a Ph.D. degree at the

University of Paris The University of Paris (), known Metonymy, metonymically as the Sorbonne (), was the leading university in Paris, France, from 1150 to 1970, except for 1793–1806 during the French Revolution. Emerging around 1150 as a corporation associated wit ...

in 1969 and 1971 under the supervision of

Claude Chevalley Claude Chevalley (; 11 February 1909 – 28 June 1984) was a French mathematician who made important contributions to number theory, algebraic geometry, class field theory, finite group theory and the theory of algebraic groups. He was a found ...

and

Pierre Deligne Pierre René, Viscount Deligne (; born 3 October 1944) is a Belgian mathematician. He is best known for work on the Weil conjectures, leading to a complete proof in 1973. He is the winner of the 2013 Abel Prize, 2008 Wolf Prize, 1988 Crafoor ...

. From 1975 to 1999, he was professor at the University of Paris VII and research director of the

CNRS The French National Centre for Scientific Research (, , CNRS) is the French state research organisation and is the largest fundamental science agency in Europe. In 2016, it employed 31,637 staff, including 11,137 tenured researchers, 13,415 eng ...

. From 1983 to 1995 he was also a professor at the

École Polytechnique (, ; also known as Polytechnique or l'X ) is a ''grande école'' located in Palaiseau, France. It specializes in science and engineering and is a founding member of the Polytechnic Institute of Paris. The school was founded in 1794 by mat ...

. From 2002 to 2009 he headed the department of mathematics at the

International Centre for Theoretical Physics The Abdus Salam International Centre for Theoretical Physics (ICTP) is a research center for physical and mathematical sciences, located in Trieste, Friuli-Venezia Giulia, Italy. The center operates under a tripartite agreement between the Gov ...

(ICTP), in

Trieste Trieste ( , ; ) is a city and seaport in northeastern Italy. It is the capital and largest city of the Regions of Italy#Autonomous regions with special statute, autonomous region of Friuli-Venezia Giulia, as well as of the Province of Trieste, ...

, Italy. He was a frequent guest scientist at

Harvard University Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...

(with

Heisuke Hironaka is a Japanese mathematician who was awarded the Fields Medal in 1970 for his contributions to algebraic geometry. Early life and education Hironaka was born on April 9, 1931 in Yamaguchi, Japan. He was inspired to study mathematics after a ...

) and

Northeastern University Northeastern University (NU or NEU) is a private university, private research university with its main campus in Boston, Massachusetts, United States. It was founded by the Boston Young Men's Christian Association in 1898 as an all-male instit ...

(with Terence Gaffney and David B. Massey). He is particularly concerned with singularity theory in the complex domain ( Milnor fibrations,

perverse sheaves The mathematical term perverse sheaves refers to the objects of certain abelian categories associated to topological spaces, which may be a real or complex manifold, or more general topologically stratified spaces, possibly singular. The concept w ...

). In 2000 he was involved in promoting scientific exchange between the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

and

Vietnam Vietnam, officially the Socialist Republic of Vietnam (SRV), is a country at the eastern edge of mainland Southeast Asia, with an area of about and a population of over 100 million, making it the world's List of countries and depende ...

. For this, he received an honorary doctorate from the Vietnam Academy of Science and Technology in 2004.ICTP release 2004
/ref> He is a Fellow of the Third World Academy of Sciences since 1993. His students include Hélène Esnault and Claude Sabbah.

Selected publications

* ''Sur les noeuds algébriques'',

Compositio Mathematica ''Compositio Mathematica'' is a monthly peer-reviewed mathematics journal established by L.E.J. Brouwer in 1935. It is owned by the Foundation Compositio Mathematica, and since 2004 it has been published on behalf of the Foundation by the London ...

25 (1972), 281-321. * with Helmut Hamm, ''Un théoreme de Zariski du type de Lefschetz'',

Annales Scientifiques de l'École Normale Supérieure ''Annales Scientifiques de l'École Normale Supérieure'' is a French scientific journal of mathematics published by the Société Mathématique de France. It was established in 1864 by the French chemist Louis Pasteur and published articles in m ...

6 (1973), 317–366. *''Calcul du nombre de cycles évanouissants d'une hyper surface complexe'',

Annales de l'Institut Fourier The ''Annales de l'Institut Fourier'' () is a French mathematical journal publishing papers in all fields of mathematics. It was established in 1949. The journal publishes one volume per year, consisting of six issues. The current editor-in-chief ...

23 (1973), 261–270
NUMDAM
* with

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 n ...

, ''The invariance of Milnor's number implies the invariance of the topological type'',

American Journal of Mathematics The ''American Journal of Mathematics'' is a bimonthly mathematics journal published by the Johns Hopkins University Press. History The ''American Journal of Mathematics'' is the oldest continuously published mathematical journal in the United S ...

98 (1976), 67–78 * ''Some remarks on relative monodromy'', Real and complex singularities 1 (Proc. Ninth Nordic Summer School), 397-403. * with Bernard Teissier, ''Variétés polaires locales et classes de Chern des variétés singulieres'',

Annals of Mathematics The ''Annals of Mathematics'' is a mathematical journal published every two months by Princeton University and the Institute for Advanced Study. History The journal was established as ''The Analyst'' in 1874 and with Joel E. Hendricks as t ...

114 (1981), 457-491. * with Francoise Michel and Claude Weber, ''Courbes polaires et topologie des courbes planes'',

, Sér.4, band 24, 1991, pp. 141–169
NUMDAM
* ''Complex analytic functions with isolated singularities'', Journal of Algebraic Geometry 1 (1992), 83-99. * with J.P. Brasselet and J. Seade, ''Euler obstruction and indices of vector fields'',

Topology Topology (from the Greek language, Greek words , and ) is the branch of mathematics concerned with the properties of a Mathematical object, geometric object that are preserved under Continuous function, continuous Deformation theory, deformat ...

39 (2000), 1193-1208.

Literature

* Jean-Paul Brasselet, José Luis Cisneros-Molina, David Massey, José Seade, Bernard Teissier (Editor) ''Singularities : international conference in honor of the 60th birthday of Lê Dũng Tráng'', Cuernavaca/Mexico 2007, 2 volumes, Contemporary Mathematics, American Mathematical Society 2008.

References

External links

Portrait at Northeastern University

David Massey, Lê's work on hypersurface singularities
{{DEFAULTSORT:Le, Dung Trang French people of Vietnamese descent 20th-century Vietnamese mathematicians Topologists 20th-century French mathematicians 21st-century French mathematicians Lycée Louis-le-Grand alumni University of Paris alumni Academic staff of Paris Diderot University Research directors of the French National Centre for Scientific Research