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Aug 26, 2016 at 22:04 vote accept Yuri Sulyma
Aug 25, 2016 at 20:18 comment added Dylan Wilson @CharlesRezk you got me
Aug 25, 2016 at 19:29 answer added Yonatan Harpaz timeline score: 21
Aug 25, 2016 at 17:39 comment added Charles Rezk It might be more interesting to think about stabilizations of slices $\infty\mathrm{Cat}_{/C}$. I'd guess that the stabilization of $\infty\mathrm{Cat}_{/\Delta^1}$ is something like spans of spectra.
Aug 25, 2016 at 17:05 comment added Charles Rezk @DylanWilson That's what I thought. BTW, assuming J is a small category, every localization of Fun(J,Spaces) wrt a set of maps is accessible, and conversely all accessible localizations arise in this way. And all presentible infty-cats are equivalent to ones obtained this way. So I don't think I have to insert "accessible" or "presentable" anywhere :P
Aug 25, 2016 at 16:56 comment added Dylan Wilson @CharlesRezk yes (after inserting 'presentable' and 'accessible' in a few places, at least). This follows from the universal property for maps out of a stabilization (that's where I use presentability), together with the universal property of maps out of a localization, right? Alternatively you could probably prove it by hand as in the proof of Higher Algebra 1.4.4.9
Aug 25, 2016 at 15:33 comment added Elden Elmanto @DenisNardin - ah alright good to know!
Aug 25, 2016 at 15:28 comment added Denis Nardin If you are interested in things that are loosely speaking homology theories on categories, one interesting keyword is noncommutative motives. (@EldenElmanto the stabilization is always linear functors from $S^{fin}_*$, no presentability assumptions needed)
Aug 25, 2016 at 15:19 history edited Yuri Sulyma CC BY-SA 3.0
clarified which question I care more about
Aug 25, 2016 at 14:29 comment added Elden Elmanto @CharlesRezk, are you thinking of describing stabilization of a presentable $C$ the localization of $Fun(S^{fin}_{\star}, C)$ at reduced and excisive functors? I think this also only works for presentable categories
Aug 25, 2016 at 13:44 comment added Charles Rezk Isn't there some formula for computing stabilizations in terms of presentations? E.g., if C is a localization of Fun(J,Spaces) at some set of maps, then it's stabilization should be a stable localization of Fun(J,Spectra) at a set of maps, no? (I'm asking, I don't really know.) If you compute this on the usual presentation of infty-Cat, you should just get spectra back.
Aug 25, 2016 at 12:42 comment added Dylan Wilson It feels like loops on some pointed category will be the space of automorphisms of the distinguished object, no? So the stabilization should just be spectra back again... To get a more interesting answer one probably needs to at least consider lax pullbacks in your definition of `loops', but I dunno
Aug 25, 2016 at 12:20 comment added Denis Nardin Note that in general you don't have a functor $\Sigma^\infty$ from a category to its stabilization, but only a functor $\Omega^\infty$ going in the other direction ($\Sigma^\infty$ exists when the category is presentable by the adjoint functor theorem). Moreover I don't think that the category of spectrally enriched categories is stable. Interesting question though.
Aug 25, 2016 at 12:15 history asked Yuri Sulyma CC BY-SA 3.0