Timeline for Why a non-simple geodesic in a Y-piece is NOT homotopic to a common perpendicular to the geodesic boundaries ?
Current License: CC BY-SA 2.5
10 events
| when toggle format | what | by | license | comment | |
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| Jan 9, 2011 at 17:44 | answer | added | ε-δ | timeline score: 3 | |
| Jan 9, 2011 at 4:17 | comment | added | Analysis Now | @ Anton Petrunin : Did you delete one of your comments ? But I guess I did not fully understand the line "If some components coincide then you get a triangle with sum of angles >π " , and here in hyperbolic cases all the triangles have angle-sum less than $ \pi $ | |
| Jan 8, 2011 at 21:12 | comment | added | Anton Petrunin | @Salp. Did you understand my the proof in my comment? | |
| Jan 8, 2011 at 5:17 | comment | added | Analysis Now | Yes, my question assumed here that we are working with a hyperbolic metric ( curvature -1 ) on Y, which I probably should have mentioned . | |
| Jan 8, 2011 at 4:51 | comment | added | Anton Petrunin | I noticed that you tag it "hyperbolic-geometry"; if curvature $\le 0$ then it is true, and your argument works. If some components coincide then you get a triangle with sum of angles $>\pi$. | |
| Jan 8, 2011 at 4:46 | answer | added | Igor Rivin | timeline score: 1 | |
| Jan 8, 2011 at 4:42 | comment | added | Igor Rivin | I believe that $Y$-piece is the classical name for this surface -- it has been completely superceded by Bill Thurston's "pair of pants" terminology. | |
| Jan 8, 2011 at 4:14 | comment | added | Dylan Thurston | Is a $Y$-piece what's also known as a pair of pants? | |
| Jan 8, 2011 at 3:48 | history | edited | Analysis Now | CC BY-SA 2.5 |
added 7 characters in body
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| Jan 8, 2011 at 3:42 | history | asked | Analysis Now | CC BY-SA 2.5 |