Henri Dulac

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Henri Claudius Rosarius Dulac (born October 3, 1870 in Fayence , † September 2, 1955 , ibid) was a French mathematician.

Life

Dulac studied from 1890 at the École Polytechnique and received a doctorate in mathematics. He taught at the universities of Grenoble , Algiers and Poitiers and in 1911 became professor of pure mathematics at the University of Lyon . During the First World War , as an officer, he commanded a company of engineering troops of the French Army. After the war he held a professorship for differential and integral calculus at the University of Lyon and also taught at the École Centrale Lyon until 1930 . He was also a long-time examiner for analysis at the École Polytechnique in Paris and temporarily president of the admissions jury.

In 1923 he published a proof that polynomial vector fields in the plane only have a finite number of limit cycles (the question of the number and position of the limit cycles is part of the 16th Hilbert problem and is unsolved). However, Juli Ilyashenko found a mistake in the 1970s. Complete evidence has been given by Ilyashenko and J. Ecalle. He also dealt with the analytical theory of objects of algebraic geometry in the successor of Émile Picard . He was involved in the publication of the works of Leonhard Euler .

Dulac was a corresponding member of the Académie des Sciences (since 1944) and an officer in the Legion of Honor .

He was the father of three children.

Fonts (selection)

  • Recherches sur les points singuliers des équations différentielles (Journal de l'École Polytechnique, 1904).
  • Intégrales d'une équation différentielle (Annales de l'université de Grenoble, 1905).
  • Sur les points dicritiques (Journal de mathématiques, 1906).
  • Sur les séries de Mac-Laurin à plusieurs variables ( Acta Mathematica , 1906).
  • Détermination et intégration d'une classe d'équations différentielles (Bulletin des sciences mathématiques, 1908).
  • Intégrales passant par un point singulier ( Rendeconti del Circolo , 1911).
  • Sur les points singuliers (Annales de Toulouse, 1912).
  • Solutions d'un système d'équations différentielles (Bulletin de la société mathématique, 1913).
  • Sur les cycles limites (Bulletin de la société mathématique, 1923).
  • Points singuliers des équations différentielles (éditeur Gauthier-Villars, 1934, Mémorial des sciences mathématiques).
  • Courbes définies par une équation différentielle du premier ordre (Mémorial des sciences mathématiques, 1934).

Web links

personal data
SURNAME Dulac, Henri
ALTERNATIVE NAMES Dulac, Henri Claudius Rosarius (full name)
BRIEF DESCRIPTION French mathematician
DATE OF BIRTH October 3, 1870
PLACE OF BIRTH Faience (Var)
DATE OF DEATH 2nd September 1955
Place of death Faience (Var)