Léon César Autonne (28 July 1859,

Odessa ODESSA is an American codename (from the German language, German: ''Organisation der ehemaligen SS-Angehörigen'', meaning: Organization of Former SS Members) coined in 1946 to cover Ratlines (World War II aftermath), Nazi underground escape-pl ...

– 12 January 1916) was a French engineer and mathematician, specializing in algebraic geometry, differential equations, and linear algebra.

Education and career

Autonne studied from 1878 to 1880 at l'

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 ...

and then at the

École des ponts et chaussées École or Ecole may refer to: * an elementary school in the French educational stages normally followed by secondary education establishments (collège and lycée) * École (river), a tributary of the Seine flowing in région Île-de-France * Éco ...

and became there ''Ingénieur en chef''. He received in 1882 from the Sorbonne his Ph.D. with dissertation ''Recherches sur les intégrales algébriques des équations differentielles à coefficients rationnels'', with

Charles Hermite Charles Hermite () FRS FRSE MIAS (24 December 1822 – 14 January 1901) was a French mathematician who did research concerning number theory, quadratic forms, invariant theory, orthogonal polynomials, elliptic functions, and algebra. Hermite p ...

as chair of the thesis committee. The dissertation was based on research initiated by

Camille Jordan Marie Ennemond Camille Jordan (; 5 January 1838 – 22 January 1922) was a French mathematician, known both for his foundational work in group theory and for his influential ''Cours d'analyse''. Biography Jordan was born in Lyon and educated at ...

. An 1891 article by Autonne in the Comptes rendus de l'Académie des Sciences de Paris is one of the earliest uses of the concept of

Lie group In mathematics, a Lie group (pronounced ) is a group (mathematics), group that is also a differentiable manifold, such that group multiplication and taking inverses are both differentiable. A manifold is a space that locally resembles Eucli ...

s (as groups of Monsieur Lie). Autonne won the Prix Dalmont in 1894. He was an

invited speaker at the International Congress of Mathematicians An invitation system is a method of encouraging people to join an organization, such as a Club (organization), club or a website. In regular society, it refers to any system whereby new members are chosen; they cannot simply apply. In relation to w ...

in 1897, 1900, 1904 and 1908. On 6 January 1902 he was made

Chevalier de la Légion d'honneur The National Order of the Legion of Honour ( ), formerly the Imperial Order of the Legion of Honour (), is the highest and most prestigious French national order of merit, both military and Civil society, civil. Currently consisting of five cl ...

. The Autonne-Takagi factorization of complex symmetric matrices is named in his honour.

Selected publications

*Recherches sur les intégrales algébriques des équations differentielles à coefficients rationnels, Gauthier-Villars 1882
Sur la théorie des équations différentielles du 1e ordre et du 1e degré
Gauthier-Villars 1891 (180 pages)
Sur la representation des courbes gauches algebriques
1896 (37 pages) *
Sur les formes quaternaires à deux séries de variables: applications à la géométrie et au calcul intégral
Hayez, 1901
Sur les formes mixtes
Annales de l'Université de Lyon, 1905
Sur les groupes de matrices linéares non invertibles
Annales de l'Université de Lyon, 1909
Sur les groupes commutatifs et pseudo-nuls de quantités hypercomplexes
Annales de l'Université de Lyon, 1912
Notice sur les recherches mathématiques
Gauthier Villars 1913 (Autonne's CV and publication list, 35 pages)
Sur les matrices hypohermitiennes et sur les matrices unitaires
Annales de l'Université de Lyon, 1915

Sources

*Henri Poincaré: La correspondance d'Henri Poincaré avec des mathématiciens de A à H, Cahiers du séminaire d'histoire des mathématiques, tome 7, 1986, p. 80 (letters from Autonne from 1881 to 1884 on the theme of the dissertation by Autonne, which were not published elsewhere; the answering letters from Poincaré are not reproduced in this source)
numdam
* Necrology (in French), ''Revue générale des sciences'', 1918, p. 33, available onlin

* Michel Dürr: "AUTONNE Léon", in Dominique Saint-Pierre (dir.), Dictionnaire historique des académiciens de Lyon 1700-2016, Lyon : Éditions de l'Académie (4, avenue Adolphe Max, 69005 Lyon), 2017, p. 80-81.

References

External links

BNF
{{DEFAULTSORT:Autonne, Leon 1859 births 1916 deaths École Polytechnique alumni École des Ponts ParisTech alumni Corps des ponts French civil engineers 19th-century French mathematicians 20th-century French mathematicians Emigrants from the Russian Empire to France