### 3000 and One Things to Think About

#### Posted by Urs Schreiber

In a burst of activity, Zoran Škoda a few minutes ago went beyond the $n$Lab entry of nominal count 3000 with beginning a discussion of crystals.

Other activity we have seen recently:

Peter Arndt just expanded the section on Chow groups at motivic cohomology.

Jacques Distler has added to the software an impressive built-in SVG-graphics editor and everyone is now drawing nice diagrams for their $n$Lab entries, such as Andrew Stacey on his page on Frölicher spaces.

David Corfield is, as you know, pushing us to look into the internal logic in an $(\infty,1)$-topos. While Mike Shulman of course is developing 2-categorical logic all along.

We found (Zoran and I did, at least) that we need to be pushing to get to more genuine physics on the $n$Lab, but also that we still need to get a bit more abstract structure in place first to do it

*right*. Sort of as a reminder for where we are headed, now an $n$POV on BV-BRST formalism in terms of derived higher geometry.But the physics is gradually coming, hopefully? There is now lots to think about at multisymplectic geometry. I am hoping for somebody to start talking about the references on multisymplectic quantization mentioned at the very end!

Or: today we figured out what exactly quantum information theorists mean by quantum channels and noticed that these obviously form a nice category.

Well, it takes its time. I have been spending a bit of time preparing notes that ought to eventually be useful in seminars on $C^\infty$-rings and the $(\infty,1)$-Grothendieck construction.

And then there is notable activity on the personal webs.

André Joyal is explaining distributors and factorization systems.

Todd Trimble is beginning to explain Buildings for category theorists.

And *you* haven’t even contributed yet! (Unless you have, of course).

## Re: 3000 and One Thing to Think about

Erp! I’d better get cracking! :-)