Timeline for Pach's "Animals": What if the genus is positive?
Current License: CC BY-SA 3.0
17 events
| when toggle format | what | by | license | comment | |
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| Feb 15, 2022 at 8:01 | comment | added | domotorp | I would only write that an alleged proof was announced, but it was never published, or confirmed to be valid by anyone else. Also, the links to the manuscripts are broken. | |
| Sep 24, 2017 at 11:49 | comment | added | Günter Rote | The term animal or lattice animal is a common term for these creatures (polyominoes, polycubes, etc.) in the physics literature. | |
| Sep 22, 2017 at 20:31 | history | edited | Joseph O'Rourke | CC BY-SA 3.0 |
Image link broken; now fixed.
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| Oct 21, 2014 at 12:59 | history | edited | Ricardo Andrade | CC BY-SA 3.0 |
removed deprecated tag 'geometry'; added top-level tags; replaced extraneous mathjax in title
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| Oct 21, 2014 at 4:16 | history | edited | Igor Pak | CC BY-SA 3.0 |
link fixed
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| May 11, 2011 at 19:24 | history | edited | Joseph O'Rourke | CC BY-SA 3.0 |
Problem now claimed to be solved.
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| Jan 3, 2011 at 21:34 | comment | added | Joseph O'Rourke | @Bill: Good questions, and I am afraid I know little. I do recall that Krystyna Kuperberg proved something like this: If every cube is replaced by $k^3$ cubes, then the answer to Pach's question is 'Yes.' I believe she established this for $k=3$. | |
| Jan 3, 2011 at 17:15 | answer | added | Gil Kalai | timeline score: 8 | |
| Jan 3, 2011 at 16:53 | comment | added | Bill Thurston | If you use a cell division of space that has 4 cells touching each vertex in place of the cubical subdivision, then this particular question becomes trivial: every union of cells has boundary a manifold. Is much known about other cell divisions, for instance the tiling by associated with the tetrahedral reflection group where the tetrahedron has two opposite 90 degree angles and all other angles 60 degrees? | |
| Jan 3, 2011 at 11:58 | history | edited | Joseph O'Rourke | CC BY-SA 2.5 |
deleted 19 characters in body
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| Jan 3, 2011 at 3:26 | comment | added | Petya | 1988 + 13 = 2001 | |
| Jan 2, 2011 at 23:46 | history | edited | Joseph O'Rourke | CC BY-SA 2.5 |
Emphasis added.; added 1 characters in body
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| Jan 2, 2011 at 23:33 | comment | added | Joseph O'Rourke | ... I often use Adobe Illustrator, e.g, mathoverflow.net/questions/50800/…, and sometime, raw Postscript: mathoverflow.net/questions/38307/… . Jack of all trades; master of none. :-) | |
| Jan 2, 2011 at 23:32 | comment | added | Joseph O'Rourke | @Andres: Thanks for asking; I am eclectic :-). That image was produced in Mathematica, whereas the Christmas tree balls in mathoverflow.net/questions/50150/… and the Thurston reflex-hull image in mathoverflow.net/questions/39378/… were constructed in POV-ray. (continued...) | |
| Jan 2, 2011 at 23:19 | comment | added | Igor Rivin | @Andres: The color scheme looks like Mathematica(tm) | |
| Jan 2, 2011 at 23:15 | comment | added | Andrés E. Caicedo | Joseph, which program do you use for your graphics? | |
| Jan 2, 2011 at 23:13 | history | asked | Joseph O'Rourke | CC BY-SA 2.5 |