Timeline for Reflection reverses a root string
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
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| May 29 at 13:37 | answer | added | Melon_Musk | timeline score: 0 | |
| Aug 28, 2019 at 20:20 | history | edited | Jim Humphreys | CC BY-SA 4.0 |
added 1 character in body; edited title
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| Aug 27, 2019 at 16:06 | history | edited | Jim Humphreys |
edited tags
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| Aug 27, 2019 at 15:38 | history | edited | Jim Humphreys | CC BY-SA 4.0 |
added 7 characters in body
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| Aug 27, 2019 at 15:37 | answer | added | Jim Humphreys | timeline score: 1 | |
| Aug 23, 2019 at 3:39 | comment | added | Torsten Schoeneberg | Crossposted and answered on math.stackexchange: math.stackexchange.com/q/3328664/96384. Please note that crosspostings are not liked too much (and this question quite obviously belongs to stackexchange). | |
| Aug 20, 2019 at 20:38 | comment | added | amator2357 | Yeah, I've been playing around with it (an inner product) but I haven't gotten anywhere yet. Anyway, thanks for your help! | |
| Aug 20, 2019 at 20:32 | comment | added | Sam Hopkins | I’m not sure of an essentially algebraic way to think about this: you’re going to have to use the fact that you have an inner product. | |
| Aug 20, 2019 at 19:57 | comment | added | amator2357 | @SamHopkins Thank you! And yeah, it makes more sense now. Do you have any hints on how to show that algebraically? | |
| Aug 20, 2019 at 18:13 | comment | added | Sam Hopkins | The elements of a root string all lie on an affine line with direction alpha (and they are the only points of the line in the root system). The points on this line furthest from the hyperplane orthogonal to alpha have to be mapped to one another via the reflection. Those furthest points are clearly the two ends of the root string. Is that geometrically obvious enough? | |
| Aug 20, 2019 at 10:25 | review | First posts | |||
| Aug 20, 2019 at 10:35 | |||||
| Aug 20, 2019 at 10:23 | history | asked | amator2357 | CC BY-SA 4.0 |