[Math] Is a come back to mathematical research possible

Question

Living in France, I am sometimes asked about Cédric Villani, a very popular figure here. Will he come back to mathematics ? The question becomes more relevant with the coming parliament elections (he should not candidate, having split with the president's party).

My impression is that it would be difficult for him. Even after a two-weeks vacations, I find a bit difficult for me to think hard on a mathematical problem ; I just cannot imagine stopping a year long.

Are there examples of mathematicians who stopped mathematics for a while (at least several years) and then resume and achieved valuable results in their second career ?

Notice that the break may have various causes, such as nervous breakdown, imprisonment, war time, … Of course, Jean Leray doesn't count, as he kept doing maths in an oflag (and what maths !).

Besides the case of women who stopped because of motherhood (I should have think of it from the beginning ; thanks to Fedor), let me mention that of chinese mathematicians who were sent to the countryside during Cultural Revolution (e.g. Hsiao Ling).

Answer 1

Alice Roth became a mathematics teacher after her Ph.D. in 1938, and only returned to research after her retirement in 1971. Her 1976 paper on the "fusion lemma" is said to have "influenced a new generation of mathematicians worldwide".

Further listening: 8 minute portrait

Further reading: Alice in Switzerland: The life and mathematics of Alice Roth

Alice Roth remained at the Humboldtianum [high school] until her retirement in 1971. It appears that shortly before retirement she had begun her transition back to work in mathematics. After announcing her plans to return to research to friends and relatives, she was told by one of them that in his field of medicine it would be impossible to return after so long an absence. Surely, most mathematicians would agree that it is impossible in the field of mathematics as well.

And so Alice Roth would seem an unlikely candidate for success. Yet much had changed in the thirty years that she had been teaching. In particular, Roth's area of research – begun over thirty years earlier – had become fashionable. [...] At last Alice Roth had time on her side and was able to put her mathematical creativity to work. She was now "am chnobble" (pondering a problem) full-time, gave talks to other mathematicians at universities, and made good progress – at the cutting edge of contemporary mathematics.

Roth's past as well as future work was to have a strong and lasting influence on mathematicians working in this area. Her Swiss cheese set has been modified (to an entire variety of cheeses); the fusion lemma which appeared in her 1976 paper influenced a new generation of mathematicians worldwide.