Timeline for Non-inherited symmetries of shadows of point sets
Current License: CC BY-SA 2.5
3 events
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| Dec 6, 2010 at 0:47 | comment | added | Peter LeFanu Lumsdaine | @Gerhard: I would agree: I don’t think one gets a map of group in either direction. I guess what one can say is: given a map $f:V \to W$ sending $\Omega_1$ to $\Omega_2$, we can say a symmetry $\sigma$ of $(V,\Omega_1)$ (“upstairs”) is $f$-related to a symmetry $\tau$ downstairs if $f \cdot \sigma = \tau \cdot f$. Then a symmetry $\tau$ downstairs is inherited if there is a symmetry $\sigma$ upstairs that is $f$-related to it? I guess something like this fits the intent of the original definition? | |
| Dec 5, 2010 at 22:45 | comment | added | Gerhard Paseman | My brain has suddenly kicked into (maybe out of) gear. What if we project an equilateral triangle onto a line? Do we not lose some symmetries that way? I am left wondering if the group inclusions written above are correct. Gerhard "Interruption Due to Technical Difficulties" Paseman, 2010.12.05 | |
| Dec 5, 2010 at 22:34 | history | answered | Gerhard Paseman | CC BY-SA 2.5 |