University of Chicago Prof. Frank Calegari has been elected to the American Academy of Arts and Sciences, one of the nation’s oldest and most prestigious honorary societies. The first members elected to the Academy, in 1781, included Benjamin Franklin and George Washington.
He joins the 2025 class, which includes world leaders in academia, business, government and public affairs whose impactful work informs policy and advances the public good.
Calegari’s research is in the area of algebraic number theory. He is particularly interested in the Langlands program, a set of mathematical ideas that has been called the "grand unified theory of mathematics.”
In 2021, Calegari and two colleagues discovered a groundbreaking proof of what’s known as the unbounded denominators conjecture. Last year, he and his collaborators followed that up by creating a new technique to prove certain numbers are irrational—significantly improving upon the previous method, which had been around since the 1970s.
Calegari is a Fellow of the American Mathematical Society and the recipient of a Sloan Fellowship and an American Institute of Mathematics Fellowship. He was a plenary speaker at the 2022 International Congress of Mathematicians.
He joined the University of Chicago in 2015, after previously serving as a professor at Northwestern University and a postdoctoral fellow at Harvard University. He received his Ph.D. in mathematics from the University of California, Berkeley.