### Categorification in Uppsala

#### Posted by David Corfield

Earlier this month the Mathematics Institute at Uppsala University hosted a conference called Categorification in Algebra and Topology, clearly a theme close to our collective heart. As yet there are only a handful of participants’ notes available (Scott Morrison’s are particularly well rendered), although the abstracts refer you to one or two others. What I’d like to have found out is whether there are differences in people’s conception of the scope of categorification.

Posted at September 21, 2006 3:29 PM UTC
## Re: Categorification in Uppsala

Ingo Runkel gave a talk titled Categorification and correlation functions in conformal field theory, reviewing work on the FRS theorem, which says something like that rational

conformal2-dimensional quantum field theory is much liketopological2-dimensional field theory, butinternalizednot in $\mathrm{Vect}$ but in some modular tensor category.This yields a very powerful formalism where you use reasoning from topological QFT all the time, and yet do get CFT correlation functions out in the end.

For those sipping $n$-categorical coffee here, I should say that I think there are indications that, while this FRS work is already deeply categorical, a deeper $n$-categorical structure is still hidden. Some remarks on that are here.