**Bernard Malgrange** is a French mathematician who worked on differential equations and singularity theory.

- Malgrange took Cartan's courses on differential geometry and Lie groups in his second year.
- Following a suggestion by Jean Dieudonné, enthusiastically supported by Henri Cartan, Malgrange and his fellow student André Blanchard spent one semester of their second year of study at the Faculty of Sciences at Nancy.
- Malgrange and Blanchard were two active participants.
- Among the topics at these seminars that Malgrange attended we mention differential topology, particularly de Rham's theorem.
- In his fourth year of study at the École Normale Supérieure, Malgrange took a course on functions of several complex variables from Henri Cartan and also attended a seminar led by Jean-Pierre Serre on the same topic.
- In 1951 Malgrange was awarded a grant by the Centre National de la Recherche Scientifique to undertake research at Nancy advised by Laurent Schwartz.
- Jacques-Louis Lions had, like Malgrange, been a student at the École Normale Supérieure, while the other student, Alexander Grothendieck, had been an undergraduate at Montpellier.
- An interesting story relating to Grothendieck's thesis was told by Malgrange, who was present at the thesis defence on 28 February 1953.
- "He told me, 'There is nothing more to do, the subject is dead'," Malgrange recalled.
- After Grothendieck's thesis defense, which took place in Paris, Malgrange recalled that he, Grothendieck, and Henri Cartan piled into a taxicab to go to lunch at the home of Laurent Schwartz.
- They took a cab because Malgrange had broken his leg skiing.
- "In the taxi Cartan explained to Grothendieck some wrong things Grothendieck had said about sheaf theory," Malgrange recalled.
- Malgrange has precisely demonstrated this existence theorem at about the same time as Léon Ehrenpreis in the United States.
- Malgrange and Ehrenpreis worked for several years on very similar topics.
- Malgrange was awarded his doctorate in 1955 from the Université Henri Poincaré at Nancy for his thesis Existence et approximation des solutions des équations aux dérivées partielles et des équations de convolution Ⓣ(Existence and approximation of solutions of partial differential equations and convolution equations).
- Even before his thesis was published, Malgrange had published a number of papers.
- Malgrange was appointed as an assistant lecturer in the Faculty of Sciences at Strasbourg in 1955 and later promoted to Professeur sans chaire.
- In 1965 Malgrange became a professor in the Faculty of Science at Orsay.
- It became a faculty in its own right on 1 March 1965 but it was a small department that Malgrange joined.
- Malgrange remained there until 1973 when he was appointed Director of Research at the Centre national de la recherche scientifique.
- Perhaps his best known result is called the Malgrange Preparation Theorem and this appeared in his classic text Ideals of differentiable functions (1966).
- This book was based on a course of lectures given by Malgrange at the Tata Institute of Fundamental Research, Bombay, India in January and February 1964.
- In 1991 Malgrange published Équations différentielles à coefficients polynomiaux Ⓣ(Differential equations with polynomial coefficients).
- Malgrange published Systèmes différentiels involutifs Ⓣ(Involutive differential systems) in 2005.
- Malgrange has received many honours.
- The Academy of Sciences has awarded Malgrange a number of prizes: the Prix Carrière in 1961, the Prix Servant in 1970 and the Prix Cognacq-Jay in 1972.

Born 6 July 1928, Paris, France.

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**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive