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Jan 14, 2020 at 14:41 answer added David White timeline score: 5
Mar 13, 2019 at 23:19 history became hot network question
Mar 13, 2019 at 22:49 vote accept Simon Henry
Mar 13, 2019 at 22:21 comment added Simon Henry @TimCampion : I thought it was in Hirschhorn's book, but he does it for "cellular" model categories instead of combinatorial. I just found the statement in Barwick "On left and right model categories and left and right bousfield localizations" as theorem 4.7. He attributed the results to J.Smith. I thought it was more "well known" than that. But maybe I missed a more classical reference.
Mar 13, 2019 at 22:03 comment added Tim Campion I see that Casacuberta and Chorny showed all Bousfield localizations exist in a left proper, combinatorial, simplicial model category. Is the "simplicial" condition removed somewhere?
Mar 13, 2019 at 22:00 answer added Reid Barton timeline score: 26
Mar 13, 2019 at 21:59 comment added Tim Campion Ah yes -- the statement that every orthogonality class is reflective is equivalent to weak Vopenka's principle -- this is 6.24 and 6.25 in Adamek and Rosicky. Example 6.25 is an example of an orthogonal subcategory in a locally presentable category which is not reflective (under the negation of weak Vopenka's principle), which I suppose answers your question in a rather artificial way.
Mar 13, 2019 at 21:44 comment added Simon Henry Though I suspect one needs the negation of Vopenka's principle to get such an example ?
Mar 13, 2019 at 21:32 comment added Simon Henry @TimCampion : good question. The left Bousfield localization at $S$ of a category where only iso are weak equivalence exists if and only if the subcategory of objects orthogonal to $S$ is reflective. it seems to me that this is not always the case when $S$ is a class, and that there might be known counter example to this ? but I haven't really thought about it.
Mar 13, 2019 at 21:18 comment added Tim Campion Is there a standard example where $S$ is a class?
Mar 13, 2019 at 21:08 history asked Simon Henry CC BY-SA 4.0