# Mathematician Who Made Sense of the Universe’s Randomness Wins Math’s Top Prize

Michel Talagrand took home the 2024 Abel Prize for his work on stochastic systems, randomness and a proof of a physics reaction that many experts thought was unsolvable

The 2024 Abel Prize—the mathematics world’s Nobel Prize equivalent—has been awarded to Michel Talagrand for his advances in describing and predicting the universe’s randomness. Talagrand’s path into mathematics was marked with personal struggle and resilience, and his recognition came as a shock to him.

“There was a total blank in my mind for at least four seconds,” Talagrand tells *Nature News*’ Davide Castelvecchi, describing when he heard the news of his award. “If I had been told an alien ship had landed in front of the White House, I would not have been more surprised.”

Talagrand’s work focuses on stochastic systems, which model random variables within a given time and space. Examples include the height of a flowing river, stock prices, a hospital’s patient count, the movement of gas molecules and even a stumbling drunkard’s swerving path. Over years of work, he came to make sense of such systems, using mathematical formulas known as inequalities, to better characterize the limits of their variability.

Where to safely build a house along a rushing waterway, or how to anticipate the growth of a bacterial population, for example, are problems with solutions that may be closely predicted using Talagrand’s methods. The water level in a river may be random, but the mathematician’s work can discern its likely maximum level, which would advise where to construct buildings to avoid flooding, writes the *New York Times*’ Kenneth Chang.

Essentially, his inequalities, which convert complex systems into geometrical terms, create precise estimates. They offer new tools for study and applications in other fields, including physics, chemistry, communications and ecology.

“There are papers posted maybe on a daily basis where the punchline is ‘now we use Talagrand’s inequalities,’” Assaf Naor, a mathematician at Princeton University, tells *Nature News*.

The Abel committee also commended another element of Talagrand’s work, which shows that even random systems have an element of predictability. For example, flipping a coin 1,000 times will predictably yield close to 500 heads and 500 tails. The same thought process can be applied to travel routes, and Talagrand’s principles provide convincing proof.

“It’s like a piece of art,” Helge Holden, a mathematician at the Norwegian University of Science and Technology and the Abel committee chair, tells *Nature News*. “The magic here is to find a good estimate, not just a rough estimate.”

Talagrand also earned recognition for providing a proof for a physics problem that many scientists thought could never be explained by pure mathematics. Giorgio Parisi shared the 2021 Nobel Prize in Physics for his 1979 work in predicting spin glasses, which describe the states and random behaviors of condensed magnetic atoms.

After five years of effort, Talagrand—and, separately, Italian physicist Francesco Guerra—provided the mathematical basis for Parisi’s work in the early 2000s.

“It’s one thing to believe that the conjecture is correct, but it’s another to prove it, and my belief was that it was a problem so difficult it could not be proved,” Parisi tells *New Scientist*’s Alex Wilkins.

“It turned out the solution was not that difficult,” Talagrand tells the *New York Times*. “But of course, you couldn’t get up in the morning and figure it out. There has to be a lot of humble work.”

The mathematician, now 72 years old, has followed a similar approach to his own life. At the age of 5 he became blind in his right eye after its retina detached, and a decade later, the same thing happened with his left eye, as a result of a genetic condition. He underwent a long treatment in a hospital, where his father, a university math professor, taught young Talagrand the discipline. A self-described average student before that second incident, he returned to school with a sharper mind for math.

“I’m not able to learn mathematics easily,” Talagrand tells *New Scientist*. “I have to work. It takes a very long time and I have a terrible memory. I forget things. So I try to work, despite handicaps, and the way I worked was trying to understand really well the simple things. Really, really well, in complete detail. And that turned out to be a successful approach.”

Talagrand, who retired in 2017 after a 43-year career working at the French National Center for Scientific Research, is the 27th recipient of the Abel Prize, which was first awarded in 2003. In addition to the honor, he will receive $700,000.