Yvonne Choquet-Bruhat (1923–2025)

Yvonne Choquet-Bruhat was born in Lille, France. Her parents were Berthe Hubert, a philosophy and literature professor, and physicist Georges Bruhat. When she was two years old, the family moved to Paris. During the German Occupation in World War II, her father was deported to the Nazi concentration camp at Sachsenhausen, where he died in 1945. Yvonne graduated from the École Normale Supérieure de Jeunes Filles and then was a teaching assistant there. In 1949, she became a research assistant at the Centre National de la Recherche Scientifique (French National Center for Scientific Research or CNRS), where mathematical physicist André Lichnerowicz invited her to become his doctoral student. She earned her PhD in 1951, and did postdoctoral research at the Institute for Advanced Study in Princeton, New Jersey. Her supervisor Jean Leray suggested that she study the dynamics of the Einstein field equations and she consulted with Albert Einstein there. In 1952, she and her first husband Léonce Fourès, a fellow mathematician, were both offered jobs at the Université de Marseille. In 1958-1959, she taught at the Université de Reims. In 1960, the couple divorced, and she remarried to mathematician Gustave Choquet. The same year, she became a professor at the Université Pierre-et-Marie-Curie (UPMC) in Paris, where she remained until her retirement in 1992. Prof. Choquet-Bruhat is one of the pioneers of the mathematics of general relativity, a set of mathematical structures and techniques used by Albert Einstein's theory of general relativity. In 1952, she was the first to prove the well-posedness of the Einstein Equations. Her work in this field has led to advances such as the calculation of gravitational waves. In 1979, Prof. Choquet-Bruhat became the first woman to be elected to the Académie des sciences française (French Academy of Sciences). She is also an elected member of the American Academy of Arts and Sciences. In 1989, she received the Legion of Honor. She is the sister of mathematician François Bruhat.