### Strings 2004, Day 1

Some photos from the Registration at the École Normale Supérieur:

The hall at the Collège de France is quite beautiful, but too small for the assembled multitude. Sacha Polyakov gave the first talk on his recent work on new gauge theories from strings on certain homogeneous spaces for supergroups (like $Osp(2|4)$). His model is $kappa$-supersymmetric. There are two ways to attempt to deal with $\kappa$-supersymmetry. One is to quantize covariantly, which is generally very thorny, made all the thornier here by the nonpolynomial form of his action. His approach is to fix the $\kappa$-supersymmetry, in which case one needs to check covariance of the quantum theory. He said that $\kappa$-supersymmetry implies conformal invariance, which I don’t think is true, and which, in any case, does not seem to be the issue.

He ended with a quote from Carl Jung, which seems only appropriate.

Mike Douglas’s talk also included a quote. This one from the poet Paul Valéry,

Tout ce qui est simple est faux, mais tout ce qui ne l’est pas est inutilisable.

a wise statement, but I still fear that Mike is studying the statistics of the empty set (or very nearly empty).

My favourite talk of the morning was Walcher’s on his work with Hori on D-branes in Landau-Ginsburg Theory.

I didn’t get very much out of Vasiliev’s talk in the afternoon, but Witten’s question afterwards was very clarifying. The conjecture seems to be that Vasiliev’s higher-spin gauge theory in the bulk AdS is equivalent to a free-field theory on the boundary. Nontrivial interactions of the bulk theory are obtained when we look at correlation functions of multi-linears in the boundary fields. Or something like that …

Rajesh Gopakumar gave a very interesting talk on rewriting free field gauge theory amplitudes in a stringy fashion (motivated by the AdS/CFT correspondence (I,II). The result looks intriguingly like an integral over the moduli space of genus-g surfaces with n punctures. The idea is to take the *integrand* and try to reconstruct the corresponding string theory.

I’ve blogged about the $a$-maximization conjecture before, but Ken Intriligator’s talk was a really nice summary, probably the highlight of the afternoon.

Thhhaaat’s all for today, folks…

Posted by distler at June 28, 2004 5:08 AM
## Re: Strings 2004, Day 1

Lots of people here, very busy conference. I was glad to meet you and also Robert Helling in person for the first time! But - sorry - I must have missed you in the lunch break. Maybe next time…

Some comments on your comments:

- - - When listening to Gopakumar’s talk I was wondering: What of this construction is new? The insight that gauge theory at large $N$ is dominated by planar diagrams with a coupling term proportional to the ‘genus’ is of course well known. So is Goakumar the first to make this observation precise by actually writing out the path integral in the planar limit?

- - - What is the implication of a-maximization to

stringyphysics?- - - Today in one of the talks the problem concerning flavor changing neutral currents in the landscape discussion which you mentioned before was briefly addressed. Did you talk for instance with Douglas about this? Is there any consensus in sight?

So much for now. Hopefully I can use the free afternoon tomorrow to write up something more detailed.