Timeline for Ways of proving that a framework is locally rigid
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 27, 2023 at 15:47 | history | edited | Pritam Majumder |
edited tags
|
|
| Sep 27, 2023 at 14:19 | comment | added | Moishe Kohan | I will write an example when I have time. But, from algebraic geometry viewpoint this is a natural and standard phenomenon of upper semicontinuity of dimension of cohomology groups. | |
| Sep 27, 2023 at 14:12 | comment | added | Pritam Majumder | @MoisheKohan Thanks. Could you please provide an example, or a reference?. | |
| Sep 27, 2023 at 13:56 | comment | added | Moishe Kohan | Your question in the 2nd paragraph has negative answer. I do not know about the rest. | |
| Sep 27, 2023 at 6:59 | history | edited | Pritam Majumder | CC BY-SA 4.0 |
added 207 characters in body
|
| Sep 26, 2023 at 17:59 | history | edited | Pritam Majumder |
edited tags
|
|
| Sep 26, 2023 at 15:59 | comment | added | YCor | @Gro-Tsen as you saw, I didn't blame Wikipedia in my comment :) | |
| Sep 26, 2023 at 15:24 | comment | added | Gro-Tsen | @YCor Amazingly, it appears that “Chebychev–Grübler–Kutzbach” may indeed be a standard (mis)spelling in the context of robotics, as this reference suggests; also, this photograph of Čebyšëv by Nadar shows that his name was at least occasionally spelled “Chebichev” in French while he was alive. At any rate, Wikipedia does not seem to be (entirely) to blame here. | |
| Sep 26, 2023 at 14:26 | comment | added | Joseph O'Rourke | Perhaps, then, look at this paper: "Epsilon local rigidity and numerical algebraic geometry," arxiv link. | |
| Sep 26, 2023 at 12:57 | comment | added | Pritam Majumder | @JosephO'Rourke Yes, I know (which is why I said just saying a graph has 2n-3 edges isn't enough to guarantee rigidity). But this is for generic configuration only. I am interested in showing rigidity for non-generic configuration. | |
| Sep 26, 2023 at 12:49 | comment | added | Joseph O'Rourke | Do you know Laman's theorem? "Let a graph $G$ have exactly $2n-3$ graph edges, where $n$ is the number of graph vertices in $G$. Then $G$ is "generically" rigid in $\mathbb{R}^2$ iff $e' \le 2n'-3$ for every subgraph of $G$ having $n'$ graph vertices and $e'$ graph edges." | |
| Sep 26, 2023 at 12:19 | comment | added | YCor | Wow, the Wikipedia users managed to mispell Chebyshev in the title of that page! | |
| Sep 26, 2023 at 12:03 | history | asked | Pritam Majumder | CC BY-SA 4.0 |