The Department of Mathematics is pleased to announce the 2024-2025 Erdős Colloquium, featuring a lecture by Professor Frank Calegari from the University of Chicago. The colloquium will be held on Monday, April 14, 2025, at 4:05 PM in Little Hall 113, with refreshments available at 3:30 PM in Little Hall 339.
Title: Two and a half millennia of irrationality in mathematics
Abstract: The discovery of irrational numbers — especially the fact that √2 is not rational — is often attributed to the Pythagorean philosopher Hippasus. According to legend, this revelation so disturbed his fellow Pythagoreans that they drowned him in a lake. In this talk, we will explore the long (often unsuccessful) history of our attempts to understand irrationality, with the goal of explaining how mathematicians now really think about these questions. Our journey will span from ancient Greece to the ancient régime, from 17th-century Basel to the present day. This talk will be accessible to undergraduate math majors.
About the Speaker
Professor Francesco “Frank” Calegari is a distinguished mathematician specializing in Number Theory and the Langlands Program. He earned his PhD from the University of California, Berkeley, in 2002. After serving as a Benjamin Pierce Assistant Professor at Harvard University, he joined the faculty at Northwestern University, later transitioning to the University of Chicago in 2015. Professor Calegari has also held prestigious positions such as a von Neumann Fellow at the Institute for Advanced Study in Princeton. His recent collaborative work with Vesselin Dimitrov and Yunqing Tang has led to groundbreaking achievements, including resolving the unbounded denominators conjecture of Atkin and Swinnerton-Dyer and advancing the theory of irrationality.
About the Erdős Colloquium
Named in honor of the legendary mathematician Paul Erdős (1913–1996), the Erdős Colloquium celebrates the spirit of pure mathematics. Erdős, a frequent visitor to the University of Florida between 1973 and 1996, left an indelible mark on the mathematical community. The colloquium was established in 1998-99 under the leadership of then-Chair Krishnaswami Alladi to commemorate Erdős’s contributions and to inspire mathematical inquiry. Each year, the series welcomes a prominent mathematician to deliver a lecture in the spirit of Erdős’s legacy.