### Link Homology in Paris

#### Posted by John Baez

With any luck, I’ll be in Paris this summer and thus able to learn more about the ‘practical applications’ of categorification to knot theory:

- Summer School on Link Homology, June 27 – July 3, 2009, at the Institut Henri Poincaré, 11 rue Pierre et Marie Curie, Paris. Organized by Christian Blanchet, Vincent Colin, Emmanuel Ferrand, Nadine Fournaiseua, Bernhard Keller and Gregor Masbaum.

There will be some mini-courses:

- Vincent COLIN : Contact homology: computations and applications.
- Peter OZSVATH : An introduction to Heegaard–Floer homology.
- Lev ROZANSKY : Matrix factorizations and link homology.
- Catharina STROPPEL : Category $O$, diagram algebras, and link homology.

I’m mainly dying to learn more about ‘category $O$’, which is a very natural category of (typically infinite-dimensional) representations of a simple Lie algebra. Of course I could just learn about it from my colleague Apoorva here at UC Riverside:

- Apoorva Khare, Functoriality of the BGG category $O$

But, Catharina Stroppel will have more to say about its application to categorified link invariants.

In case you’re wondering, ‘BGG’ is short for ‘Bernstein, Gelfand and Gelfand’. That’s because Gelfand did two-thirds of the work on this paper.

## Re: Link Homology in Paris

That’s because Gelfand did two-thirds of the work on this paper.One of the Gelfands (I’m not sure which one) is not going to appreciate that joke.