Category: Mathematics

Number Theory Days 2012

Since 2005, the number theorists at ETH Zürich and at EPF Lausanne organize every year the Number Theory Days, which present five talks, in all areas of number theory, over two days. (Actually, I’ve seen one web page claim that the tradition started in 2004, but I didn’t find any other reference for it…)

The 2012 edition will be held in Zürich on March 30 and 31, co-organized by Philippe Michel and myself, with the support of the FIM. Here is the official web page and the beautiful poster:

We especially encourage your researchers interested in attending (PhD students, postdocs, in particular) to write to the FIM coordinator, as indicated on the web page, to register, and to indicate if they wish to request funding for travel and local expenses.

The Hermann Weyl Zimmer, renovated

The first time I came to Zürich, I gave a lecture in the Number Theory Seminar. Like most seminars at ETH, it was held in the room named “Hermann Weyl Zimmer”. I learnt there the ETH blackboard-erasing technique, which is by far the best I’ve ever seen. Later, I had many occasions to enjoy the pleasant old-fashioned chairs in the back row, which are perfect when attending seminars for pleasure (in particular, when one doesn’t take notes).

Last summer, the room was renovated, and it was formally inaugurated yesterday with a nice apéro. I took a few pictures…

The quote over the statue reads

In meiner Arbeit habe ich immer versucht, das Wahre mit dem Schönen zu vereinen; wenn ich mich über das Eine oder das Andere entscheiden musste, habe ich stets das Schöne gewählt.

which means (translation mine):

In my work, I have always tried to unite the True with the Beautiful; when I had to decide between one of them, I have always chosen what was Beautiful.

or

Dans mes travaux, j’ai toujours cherché à unir le Vrai avec le Beau ; lorsque j’ai dû décider entre l’un et l’autre, j’ai toujours choisi le Beau.

(I will not attempt an Italian translation…)

Here one can see the secret ETH tool for cleaning the blackboard:

And here are the chairs:

Finally, courtesy of my new phone, a panoramic view…

Journals

Two cents on the current journal/Elsevier controversy: this recent article in the ETH online magazine indicates that commercial publishers are suing ETH for providing a scanning service, where researchers in Switzerland (members of one of the libraries belonging to the Nebis consortium) are able to ask that the ETH library scan and send them by email any article available in the library (sometimes for a fee; this service is highly convenient to access articles not available online because the stacks of the main library at ETH are not accessible to its users.)

Note that Springer and Elsevier are both explicitly mentioned as two of the plaintiffs in that case.

La cascade d’homologie

It can be very rewarding to read old mathematical papers, in terms of accessing insights and ideas that may have been filtered out in later transformations of the results they contain. In my modest experience, this does not extend to notation and terminology, and it is much easier to appreciate the insights in question after translating them into modern language and formalism. This is an area where, maybe, progress is usually fairly steady. But still, there can be exceptions. I was recently rather struck, while reading the recently published collection of letters between Henri Cartan and André Weil, to discover that when they were exchanging many letters on algebraic topology just after 1945, they used the charming name cascade for what is now known as a “long exact sequence” (in homology or cohomology). I think it is too bad this didn’t become the standard name; one could have imagined that triangles
A\rightarrow B\rightarrow C\rightarrow A[1]\rightarrow
would be called “Escherian cascades”…

Incidentally, this book of letters is very interesting to read, in no small part because of the extensive notes and comments by Michèle Audin. It is published by the SMF in the same series where letters between Grothendieck and Serre were also published a few years ago.

Random CIRM happenings

I was last week at the conference on “Number theory and its applications” which was excellently organized by C. Delaunay and F.X. Roblot at the CIRM conference center, close to Marseille. Although I don’t have last year’s excuse at the end of the Joint Math Meetings, my remarks will be just as incoherent…

  • M. Watkins showed a book he recently bought in the Canary Islands, which proves that G. Perelman is on his way to becoming a pop-culture figure:

    A cursory look at the content (though not by native Spanish speakers!) does not seem to suggest that this a serious work of mathematical scholarship…
  • For the future writer of the definitive history of analytic number theory, I offer this remark from É. Fouvry, who said one could quote him:

    … et Chebychev arrive avec une astuce de voleur de mobylette… (…and then Chebychev comes around with a trick worthy of a bicycle thief)

  • Charles Boyd, an enterprising soul worthy of homeric epithets, has ported Pari/GP to android

    The package can be downloaded here. There’s something confortable in having your phone factor the 8-th Fermat number during a post-dinner round-wine discussion… One may object that, at the moment, any syntax error causes the program to exit unceremoniously, but certainly this will soon improve. (Note: the broken screen was not caused by Paridroid…)