This time we will describe the points of the arithmetic site with Steinitz’ supernatural numbers and adele-classes.

In Bourbaki est mort, CQFD, Pierre Cartier asserts: “Yes, Bourbaki is dead. He was killed by May 68!”

The Leech lattice was, according to wikipedia, ‘originally discovered by Ernst Witt in 1940, but he did not publish his discovery’ and it ‘was later re-discovered in 1965 by John Leech’. However, there is very little evidence to support this claim.

Now that Alain Connes’ talk at the IHES is online, giving hints to prove some of the statements of the arithmetic site, we can continue our story.

From left to right: Jacques Dixmier, Jean Dieudonné, Pierre Samuel, André Weil, Jean Delsarte and Laurent Schwartz on some terrace during the 1951 ‘Ecumenical’ Bourbaki summer-conference in Pelvoux. Where, exactly, was this?

Last week, the IHES shared Pierre Cartier “Les mathématiques de Grothendieck (un survol)” (talk in English though). I don’t know whether this was part of the evening activities of the conference for Maxim Kontsevich 50th birthday (one Groth-activity/conference is quickly becoming the standard…).

For the better part of the 30ties, Ernst Witt (1) did hang out with the rest of the ‘Noetherknaben’, the group of young mathematicians around Emmy Noether (3) in Gottingen.

Roubaud’s motif (pardon the expression) for writing the announcement of Bourbaki’s death in 1968 can be read between the lines in his book Mathematics, a novel from which all quotes below are taken.

The announcement of Bourbaki’s death ends with the remarkable line:

“For God is the Alexandrov compactification of the universe.” Groth. IV.22

What has this to do with Simone Weil attending Bourbaki congresses?

“A story says that in a Paris café around 1955 Grothendieck asked his friends “what is a scheme?”. At the time only an undefined idea of “schéma” was current in Paris, meaning more or less whatever would improve on Weil’s foundations.” (McLarty in The Rising Sea)