Timeline for Units in cyclotomic fields
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
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| Aug 3, 2011 at 2:42 | comment | added | David E Speyer | @Qiaochu: Great question! I don't know. | |
| Aug 3, 2011 at 1:38 | comment | added | Qiaochu Yuan | @David: how precise can that rule of thumb be made? Is it known for what polynomials $P$ it's true that $P(\zeta_n)$ is always a unit for $n$ not contained in a union of arithmetic progressions, or something like that? | |
| Aug 2, 2011 at 16:09 | comment | added | expmat | Thanks! I guess I should have tried to play with the expression a little more... | |
| Aug 2, 2011 at 16:08 | vote | accept | expmat | ||
| Aug 2, 2011 at 15:51 | history | edited | David E Speyer | CC BY-SA 3.0 |
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| Aug 2, 2011 at 15:31 | comment | added | David E Speyer | As a rule of thumb, the only easy way to find get units in cyclotomic fields is to play with ratios of the form $(\eta^a-1)/(\eta-1)$ where $a$ is relatively prime to the order of $\eta$, so it would be very surprising if an argument like this didn't work. | |
| Aug 2, 2011 at 15:27 | history | answered | David E Speyer | CC BY-SA 3.0 |