Timeline for Where does Segal's category come from?
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
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| Nov 17, 2017 at 18:00 | comment | added | Bruno Stonek | I think Proposition 3.1.5 in Leinster's "Homotopy algebras for operads" is relevant. Namely, $\Gamma^{op}$ is the Kleisli category for the monad $1\times -$ on finite sets (and Fin is the prop for the commutative monoid operad, as you say). Similarly, $\Delta^{op}$ is the Kleisli category for the monad $1\times - \times 1$ on finite ordinals. This passage was studied more systematically by Barwick in "From operator categories to topological operads". | |
| Sep 20, 2015 at 4:42 | answer | added | Adrian Clough | timeline score: 5 | |
| Oct 9, 2013 at 22:01 | vote | accept | Qiaochu Yuan | ||
| Oct 9, 2013 at 3:58 | comment | added | Qiaochu Yuan | That's the convention Segal uses, I guess? The nLab is somewhat inconsistent about which category ought to be called Gamma. | |
| Oct 9, 2013 at 3:03 | answer | added | Tom Goodwillie | timeline score: 8 | |
| Oct 9, 2013 at 2:52 | answer | added | Peter May | timeline score: 9 | |
| Oct 9, 2013 at 2:47 | answer | added | Charles Rezk | timeline score: 6 | |
| Oct 9, 2013 at 2:16 | comment | added | Tom Goodwillie | Yes, and a Gamma-space is a functor from the opposite of Gamma to Top. Oddly, in the paper where Segal introduced all of this he never mentioned the interpretation of Gamma, the opposite of the category he used, is a skeleton of FinSet_*. | |
| Oct 9, 2013 at 1:40 | comment | added | Peter May | Segal's Gamma is not FinSet*, but its opposite. Infinite loop | |
| Oct 9, 2013 at 1:05 | history | edited | Qiaochu Yuan | CC BY-SA 3.0 |
added 312 characters in body
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| Oct 9, 2013 at 0:47 | history | asked | Qiaochu Yuan | CC BY-SA 3.0 |