Birth of a Theorem: A Mathematical Adventure (16 page)

(iii)
for all
and almost all

(iv)

Moreover,

(v)
in
L
²
(
dx dt)
,

where each (
v
_k
,
p
_k
) is a pair of
C
^∞
functions with compact support—the classical solution of the Euler equations with a well-chosen forcing
in the sense of distributions.

SIXTEEN

Princeton

Morning of February 25, 2009

Plenty of peace and quiet here! The woods, the gray squirrels, the pond, biking.

And good food! The other day in the dining hall for lunch we had a velvety pumpkin soup, just like at home, a grilled swordfish filet, very tender and well seasoned, a dessert with mulberries and cream that melted in your mouth.…

In the afternoon we’ve only just gotten back to work in our offices when the bell in the clock tower atop Fuld Hall chimes three o’clock: time to go drink tea in the common room and eat the freshly baked cakes that change every day. The madeleines in particular are irresistible, every bit as scrumptious as the ones I used to make for the boys and girls in my dormitory fifteen years ago.

Bread is a real weak point: the crispy French-style baguette is hard to find in Princeton. An even more serious deficiency, as far as products of the highest necessity are concerned, is how scandalously poor the cheese is. The fruity Comté, the delicate Rove, the fragrant Échourgnac, the smooth Brillat-Savarin, the soft Navette, the spicy Olivia, the indestructible Mimolette—I can’t find any of them anywhere. My entire family has been suffering since we got here!

Earlier this month I made a lightning visit to the West Coast, to the Mathematical Sciences Research Institute at Berkeley. The MSRI is the world’s foremost sponsor of mathematical programs and workshops, welcoming hundreds of visitors every year in addition to a smaller number of research fellows invited for extended stays. It was an emotional moment for me, being back in Berkeley, where I lived for five months in 2004.

Naturally I made a special point of visiting the Cheeseboard, my favorite place in town, a cooperative run on socialist principles (just as you’d expect—this is Berkeley, after all!) offering a selection of cheeses that would put most shops in France to shame.

I loaded up. There was even some Rove, which I knew would make my kids happy. They can’t eat enough of it. And when I complained to the people working there about how hard it is to find good cheese in Princeton, they told me to check out Murray’s the next time I go to Manhattan. Can’t wait!

The French equivalent of the MSRI is the Institut Henri Poincaré in Paris, founded in 1928 with the help of the Rockefeller Foundation and the Rothschild family. Two months ago the governing board of the IHP informed me that I had been selected as the next director of the institute—unanimously, I was told. But I didn’t accept at once. I set a number of conditions, and deliberations dragged on and on.

I was first approached about the directorship four months ago. Once the initial surprise wore off, I decided it would be an interesting experience and agreed to be considered as a candidate. I didn’t tell my colleagues at ENS-Lyon, fearing they would take it badly. Why should I want to be director of an institute when I’d refused to be director of our laboratory? Why leave Lyon for Paris when I have flourished in Lyon? And who in this day and age really wants to be head of a major scientific organization, weighed down with administrative duties and having constantly to comply with new government regulations and legislative mandates?

How naïve I was to imagine that my candidacy could remain a secret! Not in France …

My colleagues in Lyon quickly learned of it—and they were amazed. Why would a mathematician my age seek to be appointed to a position with such burdensome responsibilities? I must be hiding something, they whispered among themselves. There must be some personal secret, some private agenda.

There’s no secret. And no agenda beyond a sincere desire to do something new and challenging. But only under the right circumstances! The news wasn’t very encouraging. In fact, there wasn’t any news at all. Deliberations at the IHP seemed to have gotten bogged down.…

Would we be pushing off to Paris, then, or going back to Lyon? Perhaps neither one. Cheese or no cheese, life here is very agreeable, and I have an offer to stay at the IAS for a year, maybe longer if things go well, with a handsome salary and other benefits. And now that Claire’s been able to get on with her own research again, this is a good place for her to be too. She’s part of a team in the Department of Geosciences at Princeton that’s analyzing what may turn out to be the oldest known animal fossils—an extraordinary discovery! The leader of the team is urging her to apply for a postdoc. As it is, by coming with me to Princeton she lost her teaching position in Lyon, and by now it’s too late for her to be considered for the next round of faculty assignments.

None of this makes Claire really want to go back. Staying on here would certainly be simpler for her, and more satisfying as well. And so it’s difficult to resist the allure of Princeton. To be sure, I can’t see myself settling permanently in a place where good bread is so hard to find.… But for a few years, why not? And if the IHP can’t be bothered to come up with an attractive offer, well, there’s nothing I can do about it!

Anyway, I’d been mulling all this over for several weeks and just last night decided to send a letter to France declining the job.

But this morning, when I went to open my email, there it was, a message from the IHP saying that all my conditions had been accepted! Okay to more money, okay to no teaching duties, okay to continued research funding. All of which would have been approved in the United States as a matter of course, but in France it’s quite unheard of. Claire was reading the message over my shoulder.

“If they can be counted on to do everything they say they will, you ought to accept.”

Exactly what I was thinking. And so it’s decided: we will say goodbye to Princeton and go back to France at the end of June!

Now to tell my new colleagues here the news. No doubt some of them will understand and offer their encouragement. (Give it all you’ve got, Cédric! It’s going to be a tremendous experience, etc.) Others will be worried for me. (Cédric, have you really given this enough thought? Running an institution like that will leave you no time for your own work, etc.) One or two, I’m willing to bet, will be terribly upset with me. In any event, my diplomatic skills are going to be tested right away—in the United States rather than France!

In the midst of all this confusion, one thing is certain: nothing is more important right now than the work I’m doing with Clément.

*   *   *

The Institut Henri Poincaré (“Home of Mathematics and Theoretical Physics”) was founded in 1928 to put an end to the state of isolation in which French science found itself following World War I. Soon it was renowned not only as an institution of scientific training and research but as a cultural forum as well. Einstein lectured on general relativity there, Volterra on the use of mathematical methods in biology. The IHP was home to the first French institute of statistics and the site of the first French computer project. It was also, and not least, a place where artists mingled with scientists. Some of the surrealists found inspiration there, as the photographs and paintings of Man Ray attest.