Cécile DeWitt-Morette and Yvonne Choquet-Bruhat: a tribute to two of the women who shaped IHES

When looking back at the researchers that most importantly marked IHES, two women immediately come to mind: Cécile DeWitt-Morette and Yvonne Choquet-Bruhat.

Both of them were great scientists who contributed to theoretical physics and to mathematics at a time when it was extremely rare for women to succeed in a career in these domains. They are connected by a long history of friendship and collaboration and both their lives have intertwined with the Institute’s.

In May we had the chance to meet and discuss with two of Cécile DeWitt-Morette’s daughters, Christiane and Nicolette DeWitt, as well as with Yvonne Choquet-Bruhat’s son, Daniel Choquet. They helped us retrace Cécile’s and Yvonne’s connections to the Institute and shared some thoughts on how their mothers experienced their role as women researchers.

Cécile DeWitt Morette (1922-2017) was a French physicist, best known for having founded the Les Houches School of Physics, where generations of physicists have learned from some of the greatest scientists of the 20th and 21st centuries. Cécile helped to revive physics in Europe after World War II and she played a key role in the foundation of IHES: it is she who introduced the Institute’s founder, Léon Motchane, to Robert Oppenheimer, then Director of the Institute for Advanced Study. Their encounter gave rise to a strong relationship that lasted over the years and that allowed Léon Motchane to build IHES and his strategy as a Director.

“As a physicist, what mattered the most to her was to help other people learn and understand physics, and she would do whatever she could to help people, any person, in their endeavors.” – said Christiane DeWitt about her mother, and Nicolette continued: “She was a true public servant: she really wanted to help people in whatever endeavor they wanted to pursue”.

It is in this same spirit that for many years she played an important role as a Board member, supporting IHES through her many connections, both in France and in the United States, ensuring that the Institute succeeds in its mission.

Yvonne Choquet-Bruhat is a mathematician and a physicist. Her important contribution to the understanding of Einstein’s equations and their solutions have earned her international recognition. In particular, she was the first woman to be elected to the prestigious French Academy of Sciences. She arrived at IHES late in her career, when she had already retired and under the invitation of Thibault Damour. “For my mother, IHES was a haven of peace, a place where she always felt very welcome. The moments she enjoyed the most were the lunches at the cafeteria, which are nice occasions to interact with the visitors and other researchers in an informal context.” – Daniel Choquet explained.

Cécile and Yvonne were very close friends for many years and their relationship to IHES gave them the opportunity to meet and nurture their friendship and collaborations. They wrote several books together, among which the three volumes titled “Analysis, Manifolds and Physics”. “Certainly, the loss of Cécile was a very big loss for Yvonne.” commented Daniel Choquet. And anyone currently at IHES who had the chance to meet them would confirm how much these two strong, determined and heartwarming French ladies are missed at the Institute!