Timeline for What are the fibrant objects in the injective model structure?
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| Jun 22, 2022 at 7:16 | history | edited | CommunityBot |
replaced http://front.math.ucdavis.edu/ with https://arxiv.org/abs/
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| Apr 13, 2017 at 12:58 | history | edited | CommunityBot |
replaced http://mathoverflow.net/ with https://mathoverflow.net/
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| Dec 22, 2009 at 3:56 | comment | added | Agustí Roig | @Chris. I think this is not a major problem: J_P is (I think) a class of generating (trivial) cofibrations. In a cofibrantly generated model category structure is enough to have the RLP with respect some (trivial) cofibrations to have it with respect all of them. The problem with my answer, I believe, is that I didn't realize your weak equivalences are not those of B-G: yours are pre-sheaf weak equivalences, "open-wise" defined, theirs are sheaf weak equivalences, that is stalk-wise. Sorry for my mistake. | |
| Dec 21, 2009 at 21:06 | comment | added | Chris Schommer-Pries | So I had a brief look at the Voevodsky preprint. Right before Lemma 4.1 he introduces a class of morphisms "J_P" which is roughly the class of representable presheaves times a horn-inclusion plus a relative version of these for "distinguished squares". Then the Brown-Gernstern fibrations are those which have the right lifting property w.r.t. the maps in J_P. Unless I'm missing something this is not the same as an injective fibration, which would have the lifting property w.r.t. all levelwise cofibrations. What are the B-G cofibrations? | |
| Dec 21, 2009 at 20:09 | history | answered | Agustí Roig | CC BY-SA 2.5 |