Sofia Kovalevskaya

An analyst who built a route into research when universities kept their doors closed. The story that Ostrogradsky's calculus notes were used as wallpaper in Sofia Kovalevskaya's childhood room comes through her own recollection. Because Russian universities excluded women, she entered a marriage of convenience to study abroad, attended lectures at Heidelberg, and then studied privately with Weierstrass after Berlin refused to admit her. In 1874 Göttingen awarded a doctorate in absentia on the strength of three papers on partial differential equations, Abelian integrals, and Saturn's rings; she is widely described as the first woman to receive a doctorate in mathematics in the modern sense. Stockholm appointed her extraordinary professor in 1884 and granted her a lifetime chair in 1889. She contributed the Cauchy–Kovalevskaya theorem and major work on rigid-body rotation while also writing literature, before dying of pneumonia at 41.

This is a thought experiment about influence, not a verified historical fact.

The Cauchy–Kovalevskaya theorem gives local existence and uniqueness of analytic solutions for analytic data under a non-characteristic initial condition. We cannot measure how much her career changed the timing of later women's entry into mathematics. What it supplied was a concrete precedent: a researcher excluded by institutions nevertheless completed a doctorate, taught, edited a journal, and held a lifetime chair.