Interview with Cédric Villani

On 21 May this year, CERN had the pleasure of welcoming the mathematician Cédric Villani as part of the series of lectures organised by the Groupement des Français du CERN. The CERN Bulletin took the opportunity to ask him a few questions.


Cédric Villani (left), at SM18, alongside Frédérick Bordry, head of CERN’s Technology Department, is the director of the Institut Henri Poincaré and professor at the Université Claude Bernard Lyon 1. He was awarded the Fields Medal in 2010 for his work on Landau damping and the Boltzmann equation.

CERN Bulletin: This is your first visit to CERN – how have you found it?

Cédric Villani: It has been instructive and moving, both because of the theoretical research that CERN makes possible and because of the technological feat that it represents – truly a technological work of art!

CERN Bulletin: You are currently working on Riemannian geometry problems. Is there any link between this work and the research carried out at CERN?

Cédric Villani: All the work that I’ve done in mathematical physics builds on classical physics problems – problems that do not require me to draw on quantum mechanics, relativistic mechanics, infinitesimal or infinite quantities. In this sense, my work is completely unrelated to CERN’s research. That said, a page in the history of physics is being written here now, and one can’t help being interested.

CERN Bulletin: CERN enjoys an undeniably cosmopolitan working environment. Do you think that this is an asset for scientific research?

Cédric Villani: European cooperation comes into its own when there is a large project to be realised for which it's really essential to pool our expertise, whether for CERN, ITER or ESA and so on. CERN is a very good example of what the countries of Europe can do when they join forces.

CERN Bulletin: The discovery of the Higgs boson is the successful culmination of many years of research. What are your thoughts on the subject?

Cédric Villani: The discovery of the Higgs boson is an extraordinary accomplishment! The verification of this theory has required the deployment of considerable resources; it is pretty impressive, all of this technology built to serve the human mind. Putting it rather more grandiosely, we could say that it is a real triumph of the human mind over what we don’t understand. After the event, critics will say that it was a bit of a let-down in the end, as it is exactly what was expected. What are we going to do now?! I have confidence in my high energy colleagues to answer that question; they will find worthwhile projects to take on and fascinating theories to test.

CERN Bulletin: If you could uncover the answer to one of the mysteries of mathematical physics, which one would you choose?

Cédric Villani: Phase transition, without a doubt. What is its ultimate mathematical genesis? That’s an essential question. It’s not a yes or no question - we know that phase transitions occur - it's more a question of how. For mathematicians, the more important question is often “Why is such-and-such a phenomenon true?” rather than “Is this phenomenon true?”

CERN Bulletin: What would you be doing if you hadn't pursued mathematics?

Cédric Villani: As a child, my passion was palaeontology. It’s a very difficult discipline, involving a lot of painstaking work. Imagination, tenacity and rigour are the three qualities of both the palaeontologist and the mathematician. In mathematics, imagination is perhaps the most important; in palaeontology, it is undoubtedly tenacity.

Interview by Anaïs Schaeffer