Henri Claudius Rosarius Dulac was a French mathematician.
Life
Born in Fayence, France, Dulac graduated from École Polytechnique and obtained a Doctorate in Mathematics. He started to teach a class of mathematic analysis at University, in Grenoble, Algiers and Poitiers. Holder of a pulpit in pure mathematics in the Sciences University of Lyon in 1911, his teaching was suspended during the first world war and he had to serve as officer in the French army. After the war, he became holder of a pulpit of differential and integral calculus and also taught in École Centrale Lyon. He became examiner at École Polytechnique and President of the admission jury. Awarded Officer of Legion d'honneur, the French order established by Napoleon and associate member of the French Academy of Sciences, he published part of Euler's works and contributed to the research through many publications in France and abroad. Father of 3 children, Anie, bachelor in mathematics, Jean, graduate of École Polytechnique, 1921 and Robert, graduate of polytechnique, 1922; he died in Fayence, France, in 1955.
Work
Among his publications:
Recherches sur les points singuliers des équations différentielles.
Intégrales d'une équation différentielle.
Sur les Points dicritiques.
Sur les séries de Mac-Laurin à plusieurs variables.
Détermination et intégration d'une classe d'équations différentielles.
Intégrales passant par un point singulier.
Sur les points singuliers.
Solutions d'un système d'équations différentielles.
Sur les cycles limites.
Points singuliers des équations différentielles.
Courbes définies par une équation différentielle du premier ordre.
His researches are still mentioned or challenged by international university PHD students and professors, even a hundred years after being published. As an example:
The Center Variety of Polynomial Differential Systems – Abdu Salam Jarrah, Faculté des sciences mathématiques, Université du Nouveau Mexique, USA.
Dimension Increase and Splitting for Poincaré-Dulac Normal forms – Giuseppe Gaeta, Faculté de Mathématique de l'Université de Milan and Sebastian Walcher, chaire de Mathématique, Aix La Chapelle, Journal of Non linear Mathematical Physices.
Sources: Technica, n° 190, Nov. 1955, École Centrale Lyon, French Academy of Sciences, updated by Louis Boisgibault, his great grandson. Bendixson–Dulac theorem
