Jacqueline Lelong-Ferrand (17 February 1918,

Alès Alès (; oc, Alès) is a commune in the Gard department in the Occitanie region in southern France. It is one of the sub-prefectures of the department. It was formerly known as ''Alais''. Geography Alès lies north-northwest of Nîmes, on t ...

, France – 26 April 2014, Sceaux, France) was a French mathematician who worked on

conformal Conformal may refer to: * Conformal (software), in ASIC Software * Conformal coating in electronics * Conformal cooling channel, in injection or blow moulding * Conformal field theory in physics, such as: ** Boundary conformal field theory ...

representation theory Representation theory is a branch of mathematics that studies abstract algebraic structures by ''representing'' their elements as linear transformations of vector spaces, and studies modules over these abstract algebraic structures. In essen ...

potential theory In mathematics and mathematical physics, potential theory is the study of harmonic functions. The term "potential theory" was coined in 19th-century physics when it was realized that two fundamental forces of nature known at the time, namely gra ...

, and

Riemannian manifold In differential geometry, a Riemannian manifold or Riemannian space , so called after the German mathematician Bernhard Riemann, is a real, smooth manifold ''M'' equipped with a positive-definite inner product ''g'p'' on the tangent spac ...

s. She taught at universities in Caen, Lille, and Paris.

Education and career

Ferrand was born in

, the daughter of a classics teacher, and went to secondary school in Nîmes. In 1936 the

École Normale Supérieure École may refer to: * an elementary school in the French educational stages normally followed by secondary education Secondary education or post-primary education covers two phases on the International Standard Classification of Education sca ...

began admitting women, and she was one of the first to apply and be admitted. In 1939 she and

Roger Apéry Roger Apéry (; 14 November 1916, Rouen – 18 December 1994, Caen) was a French mathematician most remembered for Apéry's theorem, which states that is an irrational number. Here, denotes the Riemann zeta function. Biography Apéry was born ...

placed first in the mathematics

agrégation In France, the ''agrégation'' () is a competitive examination for civil service in the French public education system. Candidates for the examination, or ''agrégatifs'', become ''agrégés'' once they are admitted to the position of ''profess ...

; she began teaching at a girls' school in

Sèvres Sèvres (, ) is a commune in the southwestern suburbs of Paris, France. It is located from the centre of Paris, in the Hauts-de-Seine department, Île-de-France region. The commune, which had a population of 23,251 as of 2018, is known for ...

, while continuing to do mathematics research under the supervision of

Arnaud Denjoy Arnaud Denjoy (; 5 January 1884 – 21 January 1974) was a French mathematician. Biography Denjoy was born in Auch, Gers. His contributions include work in harmonic analysis and differential equations. His integral was the first to be able to i ...

, publishing three papers in 1941 and defending a doctoral thesis in 1942. In 1943 she won the Girbal-Baral Prize of the

French Academy of Sciences The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research. It was at th ...

, and obtained a faculty position at the

University of Bordeaux The University of Bordeaux (French: ''Université de Bordeaux'') is a public university based in Nouvelle-Aquitaine in southwestern France. It has several campuses in the cities and towns of Bordeaux, Dax, Gradignan, Périgueux, Pessac, an ...

. She moved to the

University of Caen The University of Caen Normandy (French: ''Université de Caen Normandie''), also known as Unicaen, is a public university in Caen, France. History The institution was founded in 1432 by John of Lancaster, 1st Duke of Bedford, the first recto ...

in 1945, was given a chair at the

University of Lille The University of Lille (french: Université de Lille, abbreviated as ULille, UDL or univ-lille) is a French public research university based in Lille, Hauts-de-France. It has its origins in the University of Douai (1559), and resulted from the m ...

in 1948, and in 1956 moved to the

University of Paris The University of Paris (french: link=no, Université de Paris), Metonymy, metonymically known as the Sorbonne (), was the leading university in Paris, France, active from 1150 to 1970, with the exception between 1793 and 1806 under the French Revo ...

as a full professor. She retired in 1984.Biographies of Women Mathematicians

Agnes Scott College Agnes Scott College is a private women's liberal arts college in Decatur, Georgia. The college enrolls approximately 1,000 undergraduate and graduate students. The college is affiliated with the Presbyterian Church and is considered one of the ...

; accessed 5 May 2014..

Contributions

Ferrand had nearly 100 mathematical publications, including ten books, and was active in mathematical research into her late 70s. One of her accomplishments, in 1971, was to prove the

compactness In mathematics, specifically general topology, compactness is a property that seeks to generalize the notion of a closed and bounded subset of Euclidean space by making precise the idea of a space having no "punctures" or "missing endpoints", i ...

of the group of conformal mappings of a non-spherical compact

, resolving a conjecture of

André Lichnerowicz André Lichnerowicz (January 21, 1915, Bourbon-l'Archambault – December 11, 1998, Paris) was a noted French differential geometer and mathematical physicist of Polish descent. He is considered the founder of modern Poisson geometry. Biography H ...

, and on the basis of this work she became an invited speaker at the 1974

International Congress of Mathematicians The International Congress of Mathematicians (ICM) is the largest conference for the topic of mathematics. It meets once every four years, hosted by the International Mathematical Union (IMU). The Fields Medals, the Nevanlinna Prize (to be rename ...

Vancouver Vancouver ( ) is a major city in western Canada, located in the Lower Mainland region of British Columbia. As the most populous city in the province, the 2021 Canadian census recorded 662,248 people in the city, up from 631,486 in 2016. Th ...

Personal life

She married mathematician

Pierre Lelong Pierre Lelong (14 March 1912 Paris – 12 October 2011)
at the académie des sciences was a Fr ...

in 1947, taking his surname alongside hers in her subsequent publications until their separation in 1977.

References

Links

ChronoMath, une chronologie des MATHÉMATIQUES
; accessed 5 May 2014 {{DEFAULTSORT:Ferrand, Jacqueline 1918 births 2014 deaths École Normale Supérieure alumni French mathematicians Women mathematicians People from Alès 20th-century French women scientists