September 27, 1904 - January 6, 1990

Sophie Piccard was born in St. Petersburg, Russia, in 1904, to a French-Swiss father and a Russian mother. She received her Diploma in Mathematics and the Physical Sciences in 1925 from the University of Smolensk, then fled to Switzerland with her parents due to the serious social troubles in Russia. Because her diploma from Russia was not recognized in Switzerland, she began new academic studies at the University of Lausanne, earning another mathematics degree in 1927 and her doctorate in 1929. Finding doors closed to her in secondary education, however, she worked from 1929 until 1932 as an actuary, and then for several years as an executive secretary to the local newspaper. Having a desire to continue her mathematical research, she joined the faculty at the University of Neuchâtel in Switzerland in 1936 as a part-time lecturer in higher geometry despite no previous experience in teaching. She succeeded the ill Professor Gaberel, who had personally defended Piccard as an exceptional mathematician. In 1938 she was named a "professor extraordinarius" of higher geometry (roughly equivalent to associate professor) and a part-time lecturer in the field of actuarial science and the theory of probability.

In 1939 Piccard published her book "Sur les ensembles de distances des ensembles de points d'un espace Euclidean." If *A* and *B* are point sets of a Euclidean space, the distance set of the pair *(A,B)*, denoted by *D(A,B)*, is the set of all numbers *d* such that there is a pair of points, one in *A* and the other in *B*, whose distance is *d*. Piccard's book made a detailed study of various questions concerning *D(A,B)*. The review of the book in *Mathematical Reviews* said that "a few results in the field under investigation are due to Steinhaus, Sierpinski and Ruziewicz, but after chapter I, the results are almost entirely new."

In 1940 Piccard founded the Center of Pure Mathematics for which she became the director. Known for her pronounced Russian temperament, she had difficult relationships with her colleagues. Nevertheless, in 1943 she became the first woman to receive the title of "professor ordinarius" (full professor) in a Swiss university. She published over 100 papers. The first edition of Who's Who in the World reports that her work was on

Research on set theory, theory of groups of finite order, theorems about generators and relations of abstract groups; introduced notion of fundamental group and P-product of groups; discovered wide and various classes of P groups; studies in linear algebra, theory of relations and history of math.

Piccard was a member of the mathematical societies of the United States, Austria, France, Poland, and Switzerland, as well as the Association Francaise pour l'Advancement des Sciences and the Société Helvétique des Sciences Naturelles. After the death of her mother, Eulalie Piccard, in 1957, Sophie devoted much of her time to the publication of her mother's literary works. But Sophie also continued to publish mathematical articles into her eighties. She died in Freiburg in 1990.

- Who's Who in the World, 1971-72, Marquis Who's Who, Inc. 1970.
- Piccard, Sophie, entry from the Biographical Dictionary of Women in Science: Pioneering Lives from Ancient Times to the Mid-20th Century, Volume 2.
- MathSciNet [subscription required]
- Author Profile at zbMath