Sofia Kovalevskaya made a variety of original contributions to the field of mathematics. She was the first important Russian female mathematician, the first woman to receive a full professorship in Northern Europe, and one of the first women to be an editor at a scientific journal. These firsts did not come easy, though, as women in Russia were not allowed to attend university. Nor could women study abroad unless they received written permission from their father or husband. In order for Sofia to continue her mathematical studies, she entered into a fictitious marriage with paleontology student Vladimir Kovalevskij (who would later collaborate with Charles Darwin), and emigrated from Russia.
For two years Sofia studied at the University of Heidelberg in German, where women could audit classes if the professors approved. Two years later she moved to Berlin, where she took private lessons with Karl Weierstrass (considered to be “the father of modern analysis”). For her doctoral dissertation, Sofia presented three papers (on partial differential equations, elliptic integrals, and the dynamics of Saturn’s rings) to the University of Gattingen. Through Weierstrass’ support, she was able to earn her Ph.D in mathematics summa cum laude without the required lectures and exams. Additionally, one of the theorems in her paper on partial differential equations is now known as the Cauchy-Kovalevskaya theorem.
In 1883, Sofia moved to Sweden. There she became a “Professor Extraordinarius” and the editor of Acta Mathematica. She won the French Academy of Science’s Prix Bordin award in 1888, and her submission included the discovery what is now known as the “Kovalevskaya Top.” In 1889 she became a Professorial Chair holder at Stockholm University. She was even granted a Chair in the Russian Academy of Sciences (the rules were changed for her), but despite her groundbreaking work, Sofia was never offered a professorship in her native Russia.