Timeline for Counterexample for the Skolem-Noether Theorem
Current License: CC BY-SA 4.0
4 events
| when toggle format | what | by | license | comment | |
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| Jul 5, 2018 at 12:51 | history | edited | YCor | CC BY-SA 4.0 |
added tag, added capitals, added link...
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| Jul 5, 2018 at 12:04 | answer | added | Gro-Tsen | timeline score: 6 | |
| Jul 5, 2018 at 10:23 | comment | added | YCor | So it's enough to find a division ring and an injective, non-surjective endomorphism. Consider the free group over $(x_n)_{n\ge 0}$, and the endomorphism induced by $x_n\mapsto x_{n+1}$. Extend it to an endomorphism of the group ring (over some given field $k$). This is an Ore domain, so I guess this extends to an injective, non-surjective endomorphism of the right division ring of fractions, whose center is reduced to $k$. But I haven't checked details. | |
| Jul 5, 2018 at 9:52 | history | asked | user15749 | CC BY-SA 4.0 |