Number Theory

When Ellen Eischen, von Neumann Fellow (2024–25) in the School of Mathematics, followed a stray thread of “lost math” into the Institute’s Shelby White and Leon Levy Archives Center, she uncovered the story of Hel Braun—and a mid-century perspective that still has consequences for research today. Eischen's investigations show what mathematics can forfeit when it treats its truths as untouched by the human, institutional, and political realities that shape them.

The fundamental lemma has been described as a gross understatement. Says Andrew Wiles, a Visitor in the School of Mathematics and an Institute Trustee, “At first, it was thought to be a minor irritant, but it subsequently became clear that it was not a lemma but rather a central problem in the field.”