Tuesday 7 July 2009

ct.category theory - What is known about higher-categorical reconstruction theorems? (reference request)

The answer to my question is almost certainly "not much" — at least, I've asked a few people, and that was their answer. But I'd like to refine this answer, and MathOverflow seems like the best place.



I learned from David Ben-Zvi in an answer to this question the following theorem:




Let $mathcal C$ be a 1-category, and consider the category $operatorname{Rep}(mathcal C)$ of 1-functors $mathcal C to operatorname{1Vect}$. It is a (symmetric) monoidal category by "pointwise tensor product", i.e. pulling back along the diagonal map $mathcal C to mathcal C^{times 2}$. Conversely, we can consider some sort of "spec" of $operatorname{Rep}(mathcal C)$, namely the category of monoidal functors (and monoidal natural transformations) $operatorname{Rep}(mathcal C) to operatorname{1Vect}$. In fact, this "spec" is equivalent as a category to $mathcal C$.




Given this, it is natural to ask the following three questions (or combinations thereof):



  • Recognition: which monoidal categories are of the form $operatorname{Rep}(mathcal C)$ for some $mathcal C$?

  • Bump up $n$: modulo definitions, it is clear what the statement is with "$1$" replaced by "$n$". For example, the "$0$" version of the above says that a set is recoverable up to isomorphism from its algebra of all functions (the 0-category $operatorname{0Vect}$ is precisely the ground field).

  • Internalize: is there a similar statement for "topological categories" and "continuous functors", for example? A version of in algebrogeometric land is in these questions (see also the answer here).

I'm not asking for definite answers to any of these directions, because I expect that telling the complete story is hard. But I am hoping for references to the existing literature. Hence: "What's already known (in the literature) about higher-categorical reconstruction theorems?"

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