bio  website  math.berkeley.edu/~theojf 

location  Berkeley  
age  29  
visits  member for  4 years, 9 months 
seen  yesterday  
stats  profile views  13,784 
I am a recent graduate from UC Berkeley. Starting Fall 2013, I am a Boas Assistant Professor at Northwestern University. My research is broadly centered on quantum field theory — my interests include category theory, representation theory, homological algebra, algebraic topology, Poisson geometry, and theoretical physics.
1d

comment 
Removing an article from arxiv
Never use that journal. 
2d

comment 
When does a monoidal functor between ribbon categories preserve cups and caps, but not necessarily braidings?
Right. The strong monoidal functor from supervector spaces to $(\mathbb Z/2)$modules (with the usual symmetric structure) does not preserve quantum dimension. And any two (right, say) duals are canonically isomorphic, but that isomorphism often is not the identity for some looksconvenient coordinates. 
Jul 14 
comment 
Are there isomeasure simplices?
I assume you are familiar with Schanuel's excellent paper "What is the length of a potato?", but your notion of isomeasure reminded me of it, so in the off chance you don't know that paper, I thought I'd mention it. 
Jul 7 
comment 
When is/isn't the monoidal unit compact projective?
@NoahSnyder Thanks! And indeed I should have remembered that from your paper with Chris and Chris. 
Jul 6 
comment 
When is/isn't the monoidal unit compact projective?
@QiaochuYuan In TemperleyLieb? No. It's the free monoidal category on a selfdual object of that dimension. Given any monoidal category, you can ask how many braidings it admits. In the case of TL, there are precisely four (which are interchanged under $q \mapsto q$ and $q\mapsto q^{1}$). 
Jul 5 
asked  When is/isn't the monoidal unit compact projective? 
Jul 2 
awarded  Socratic 
Jul 2 
awarded  Inquisitive 
Jul 2 
awarded  Curious 
Jun 29 
comment 
Universal ribbon category of ribbon graphs
+1 to the edited version. 
Jun 3 
comment 
If $M$ has hyperkaehler structure then $M//G$ has hyperkaehler structure?
I have seen this Kahler quotient called $M //// G$, in keeping with the idea that in $M//G$ we subtract $G$ off twice. 
May 29 
awarded  Nice Question 
May 10 
comment 
Last Status of Feferman's Conjecture on Indefinite Value of Continuum
I think your question is a good one, but I disagree with your introduction. With the caveat that I'm not a set theorist, it has always seemed to me that $2^{\aleph_0}$ is a perfectly definite number — the question that ZF doesn't answer is rather "how big is $\aleph_1$?". 
May 6 
awarded  Nice Question 
May 6 
reviewed  Leave Open Does Grothendieck have any pseudonymous paper? 
May 3 
awarded  Popular Question 
Apr 30 
comment 
Are there infinitely many natural numbers not covered by one of these 7 polynomials?
This reads a bit like a homework problem. Please read meta.mathoverflow.net/questions/70, and think about moving your question to our sister site, Math.StackExchange. 
Apr 30 
accepted  I think I have a category enriched in $(\infty,n1)$categories. Is it an $(\infty,n)$category? 
Apr 24 
awarded  Reviewer 
Apr 24 
reviewed  Leave Open When distance nonincreasing map is an isometry 