November was a good month for Robert McCann. A very good month.

In addition to receiving the 2026 CRM-Fields-PIMS prize for his “unparalleled contributions to the foundations and applications of the theory of optimal transportation and the impact of his work on the development of mathematics, physics and economics, as well as his leadership in the mathematical sciences community,” the University of Toronto professor learned he had been cross-appointed to the university’s Economics Department. It’s a formality that acknowledges the importance of his mathematical research across multiple disciplines.

Both honours are connected. Dr. McCann was recognized by the prize committee for his role in shaping the modern trajectory of optimal transport by formulating the key questions, identifying structural principles and synthesizing ideas across diverse mathematical domains. His analytical framework of optimal transport has been applied to economic models of matching and equilibrium, where optimal transport maps describe optimal allocations of agents to contracts (or to goods). Hence the cross-appointment.

While he is “thrilled” to be honoured by his peers, he received the news with peak academic gallows humour.

“Let me tell you a story about an economics professor from the University of Chicago,” he said. “When he received the call that he won the Nobel Prize, he was asked how he felt and responded, ‘Well you know, I’m frankly relieved, because so many of my colleagues have Nobel Prizes I felt like I wasn’t pulling my weight in the department.’”

Jokes aside, no one would ever make that claim about him. After completing his PhD in 1994 at Princeton, Dr. McCann taught at Brown University before landing in Toronto in 1998, where he has been a fixture at the Mathematics Department ever since.

While he started out in mathematical physics, he found early success through the introduction of displacement convexity, a concept which has become central to modern optimal transport theory. This led to the linking of optimal transport with geometric notions of curvature and was at the foundation of a robust theory of metric measure spaces, a rapidly developing branch of modern mathematics.

Dr. McCann has also made significant contributions to the regularity theory of optimal transport maps, particularly in connection to the curvature and convexity properties of the underlying spaces.

“It’s been a wonderful lens for me. It was a new set of techniques that I helped to popularize and develop ever since I was a PhD student. Using this new set of techniques, I could try tackling problems from different areas of math: geometry, partial differential equations, and also in areas of cross-application. I’ve worked a lot in economics, trying to figure out how supply will equilibrate with demand to determine prices,” he said.

More recently, he has returned to the place he started 25 years ago: mathematical physics. His current collaborations include the development of a nonsmooth theory of gravity, and giving the first complete and correct solution to the monopolist's problem in the plane - a central paradigm for making microeconomic decisions facing informational asymmetry.

When he delivers the CRM-Fields-PIMS Prize lecture some time in 2026, it will mark the 25th year since he organized his first Fields event, “Problems and Perspectives on the Calculus of Variations: Physics, Economics, and Geometry,’’ which was memorably rechristened “Transport me to Toronto!”

For those outside the city who would like to experience Dr. McCann’s talk in person, we encourage you to consult proceedings from that event for the best possible route.

Photo credit: Canadian Mathematical Society (CMS)