A mathematician who tamed a nightmarish family of equations that behave so badly they make no sense has won the most lucrative prize in academia.
Martin Hairer, an Austrian-British researcher at Imperial College London, is the winner of the 2021 Breakthrough prize for mathematics, an annual $3m (£2.3m) award that has come to rival the Nobels in terms of kudos and prestige.
Hairer landed the prize for his work on stochastic analysis, a field that describes how random effects turn the maths of things like stirring a cup of tea, the growth of a forest fire, or the spread of a water droplet that has fallen on a tissue into a fiendishly complex problem.
His major work, a 180-page treatise that introduced the world to “regularity structures”, so stunned his colleagues that one suggested it must have been transmitted to Hairer by a more intelligent alien civilisation.
Hairer, who rents a London flat with his wife and fellow Imperial mathematician, Xue-Mei Li, heard he had won the prize in a Skype call while the UK was still in lockdown. “It was completely unexpected,” he said. “I didn’t think about it at all, so it was a complete shock. We couldn’t go out or anything, so we celebrated at home.”
The award is one of several Breakthrough prizes announced each year by a foundation set up by the Israeli-Russian investor Yuri Milner and Facebook’s Mark Zuckerberg. A committee of previous recipients chooses the winners who are all leading lights in mathematics and the sciences.
Other winners announced on Thursday include a Hong Kong scientist, Dennis Lo, who was inspired by a 3D Harry Potter movie to develop a test for genetic mutations in DNA shed by unborn babies, and a team of physicists whose experiments revealed that if extra dimensions of reality exist, they are curled up smaller than a third of a hair’s width.
Yet another winner, Catherine Dulac at Harvard University, has overturned misconceptions around parenthood by showing that the neural circuits for maternal and paternal behaviour are found in both males and females.
Hairer grew up in Geneva where he soon established himself as a rare talent. His entry for a school science competition became Amadeus – “the Swiss army knife of sound editing” – now used in updated form by music producers and games designers. He still maintains the software as a sideline to his academic work.
After dallying with physics at university, Hairer moved into mathematics. The realisation that ideas in theoretical physics can be overturned and swiftly consigned to the dustbin did not appeal. “I wouldn’t really want to put my name to a result that could be superseded by something else three years later,” he said. “In mathematics, if you obtain a result then that is it. It’s the universality of mathematics, you discover absolute truths.”
Hairer’s expertise lies in stochastic partial differential equations, a branch of mathematics that describes how randomness throws disorder into processes such as the movement of wind in a wind tunnel or the creeping boundary of a water droplet landing on a tissue. When the randomness is strong enough, solutions to the equations get out of control. “In some cases, the solutions fluctuate so wildly that it is not even clear what the equation meant in the first place,” he said.
With the invention of regularity structures, Hairer showed how the infinitely jagged noise that threw his equations into chaos could be reframed and tamed. When he published the theory in 2014, it made an immediate splash. “Like everyone else, I was amazed to see a theory like this, worked out in detail from scratch, with few precedents,” said Jeremy Quastel, a mathematician at the University of Toronto who first mused on the extraterrestrial provenance of the theory.
While his peers roundly consider Hairer a genius, he admits mathematics can be infuriating. “Most of the time it doesn’t work out. As pretty much every single graduate student in mathematics can attest, during your PhD you probably spend two-thirds of your time getting stuck and banging your head against a wall.”
Hairer’s windfall has yet to land in his bank account, but when it does, his life will change. “We moved to London somewhat recently, three years ago, and we are still renting. So it might be time to buy a place to live,” he said.
