Timeline for One-step problems in geometry
Current License: CC BY-SA 4.0
16 events
| when toggle format | what | by | license | comment | |
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| Apr 1, 2022 at 18:06 | comment | added | Denis Serre | Just to complete the argument and to make clear where the hypothesis is used: $A$ is entirely outside of the unit ball centered at $O$, hence the projection of $A$ over $A'$ is $1$-Lipschitz. | |
| Jul 13, 2021 at 15:06 | history | edited | Alexandre Eremenko | CC BY-SA 4.0 |
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| Jul 13, 2021 at 14:56 | history | edited | Alexandre Eremenko | CC BY-SA 4.0 |
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| Oct 12, 2017 at 14:10 | history | edited | Alexandre Eremenko | CC BY-SA 3.0 |
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| Jun 14, 2017 at 18:41 | history | edited | Alexandre Eremenko | CC BY-SA 3.0 |
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| Sep 28, 2013 at 12:51 | comment | added | Alexandre Eremenko | @Wlodzimierz: The distance between two sets is the infimum of distances between a,b, where a is in one set and b is in another set. | |
| Sep 28, 2013 at 4:24 | comment | added | Anton Petrunin | @AlexandreEremenko, no rush, I keep polishing my list of problems. Your paper is a better reference (no normal person today will read 50-pages-long-paper). | |
| Sep 28, 2013 at 3:55 | comment | added | Włodzimierz Holsztyński | @Alexandre: "the distance between these curves is 1.". How is it defined? | |
| Sep 28, 2013 at 2:25 | history | edited | Alexandre Eremenko | CC BY-SA 3.0 |
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| Sep 28, 2013 at 2:17 | comment | added | Alexandre Eremenko | @Anton: Google is really powerful: I forgot that I have this file:-) I am reluctant to submit this to arxiv, especially because a similar solution has already been submitted (see the first comment on my posting). Let me try to insert it to my MO posting. Then you can refer to it. OK? | |
| Sep 26, 2013 at 16:37 | comment | added | Anton Petrunin | @AlexandreEremenko, Google found this math.purdue.edu/~eremenko/dvi/gehring.pdf for me. Are you planning to submit it to arXiv? (Otherwise it is hard to use as a reference.) | |
| Nov 11, 2012 at 20:08 | comment | added | Alexandre Eremenko | The situation reminds me the famous problem of J-J. Sylvester: "Can we have a configuration of finitely many lines in the (real) projective plane such that all intersections are triple." (There is such a configuration in the complex projective plane $C^2$.) In the beginning of XX century this was a famous unsolved problem, sometimes listed next to the "4-colors problem". In 1944 it was solved, and the solution is such that it could be found by a clever high school kid. Also about 2 lines of text, using nothing. | |
| Nov 11, 2012 at 19:57 | comment | added | Alexandre Eremenko | Yes, this is the same proof:-) But the student was UNDERgraduate:-) I add, that Gehring, when stating the problem, added that he could prove that $length(A)\geq c$, where $c$ is an absolute constant. No one EXPECTED that the solution could be THAT simple. | |
| Nov 11, 2012 at 18:17 | comment | added | Anton Petrunin | Yes, it is a good one, thank you. Is the proof linked by jc is the same as the proof of the graduate student you mentioned? | |
| Nov 11, 2012 at 16:13 | comment | added | j.c. | There is a 4-sentence solution attributed to Marvin Ortel written up in the first few lines of the paper "Criticality for the Gehring link problem" by Cantarella et al arxiv.org/abs/math.DG/0402212 Is it by chance the one you heard? | |
| Nov 11, 2012 at 14:53 | history | answered | Alexandre Eremenko | CC BY-SA 3.0 |