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Timeline for Why do we need model categories?

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Jan 2, 2018 at 8:08 comment added Aaron Mazel-Gee I think there's some really great usage of model categories for explicit computations in the world of synthetic differential geometry -- I learned about this in Urs Schreiber's short note ncatlab.org/schreiber/files/dcct170811.pdf. It has also been necessary to use model categories to study algebras over "necessarily algebraic" operads (such as the Lie and Poisson operads), though as of fairly recently there is a theory of enriched $\infty$-operads (arxiv.org/abs/1707.08049).
Dec 6, 2017 at 19:07 answer added Edouard timeline score: 7
Dec 5, 2017 at 3:03 review Close votes
Dec 5, 2017 at 21:59
Dec 3, 2017 at 11:54 comment added the L One reason we need model categories: to do calculations in the homotopy category of a model category. That is, given a category and a set of morphisms we wish to invert, if you know that these morphisms are the weak equivalnces of a model category, it becomes much easier to do calculations in the localized category.
Nov 30, 2017 at 12:27 answer added მამუკა ჯიბლაძე timeline score: 7
Nov 29, 2017 at 2:19 answer added Dmitri Pavlov timeline score: 17
Nov 27, 2017 at 19:10 answer added AAK timeline score: 24
Nov 27, 2017 at 19:05 comment added Asaf Karagila For the same reasons we need model citizens, I guess. :)
Nov 27, 2017 at 17:00 answer added user13113 timeline score: 14
Nov 27, 2017 at 15:54 review Close votes
Nov 27, 2017 at 17:37
Nov 27, 2017 at 15:43 comment added Simon Henry In my opinion these are different questions: The other ones was explicitly about whether or not $\infty$-categories could replace model categories, which is a rather different issue than why do we need model categories in the first place, why this specific definition and whether they appears outside of algebraic topology.
Nov 27, 2017 at 15:37 comment added David White Possible duplicate of Do we still need model categories?
Nov 27, 2017 at 15:36 answer added David White timeline score: 10
Nov 27, 2017 at 15:35 history edited Qfwfq CC BY-SA 3.0
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Nov 27, 2017 at 15:33 comment added Dylan Wilson (contd) It has become increasingly accepted that a suitable candidate for what "homotopy theories" are is the notion of an $\infty$-category. Please note I am making no comment or claims on the other parts of your question.
Nov 27, 2017 at 15:33 comment added Dylan Wilson I would like to address the "philosophical" part of your question. People often forget about 0.3-0.4 in the introduction to Quillen's book inventing model categories: he himself distinguishes between a "model category" and the "homotopy theory" it models, hence the name! He then goes on to lament the absence of a satisfactory theory for what the actual "homotopy theory" should be. I think he viewed his theory just as a convenient formalism for carrying over arguments from homotopy theory to other contexts. (contd)
Nov 27, 2017 at 15:28 answer added Simon Henry timeline score: 18
Nov 27, 2017 at 15:25 answer added Lennart Meier timeline score: 38
Nov 27, 2017 at 15:06 comment added Ali Caglayan Peter May gives an excellent answer to this question that might be worth reading.
Nov 27, 2017 at 14:50 history asked Megan CC BY-SA 3.0