Timeline for Matrix from a homomorphism of simply connected groups
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
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| Aug 5, 2015 at 23:17 | history | edited | Jim Humphreys |
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| Aug 4, 2015 at 4:21 | vote | accept | Mikhail Borovoi | ||
| Aug 3, 2015 at 20:54 | answer | added | Jim Humphreys | timeline score: 4 | |
| Aug 3, 2015 at 18:19 | history | edited | Mikhail Borovoi | CC BY-SA 3.0 |
added 49 characters in body
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| Aug 3, 2015 at 17:49 | comment | added | Mikhail Borovoi | Thank you, Jason. I indeed want "here is how I would try to it", also for some orthogonal representation of another group $H$. However, I have in mind another kind of approach: to use somehow tables from Bourbaki or from Onishchik and Vinberg, and I don't know how to use those tables for my question... | |
| Aug 3, 2015 at 17:31 | comment | added | Jason Starr | Probably you want the matrix, and not a "here's how I would try to do it" comment. Nonetheless: here is how I would try to do it. For each of the minimal parabolic groups $P_H$ properly containing $B_H$, and for each of the maximal parabolic subgroups $P_G$ properly contained in $G$, $P_H/B_H$ is a $\mathbb{P}^1$ that maps to $G/P_G$. It is possible to compute the degree on this $\mathbb{P}^1$ of the ample generator of the Picard group of $G/P_G$ by localization with respect to the $2$ fixed points for the action of the maximal torus. Of course I am not saying that is easy . . . | |
| Aug 3, 2015 at 17:19 | history | asked | Mikhail Borovoi | CC BY-SA 3.0 |