Timeline for $\Lambda$-Ring Structures on $\mathbb A^2$
Current License: CC BY-SA 3.0
4 events
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| Apr 11, 2013 at 21:41 | history | edited | Will Sawin | CC BY-SA 3.0 |
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| Nov 14, 2012 at 1:17 | comment | added | Will Sawin | Yes, that's roughly how I think about them. Indeed, one can view the overlap between constructions 1 and 3 as the K-theory of the semisimple Lie group $SL_2 \times SL_2$. I chose this way for its compactness of presentation, but opinions on which is best can of course differ. | |
| Nov 13, 2012 at 20:27 | comment | added | Ben Wieland | (1) I think it's better to overcount and explicitly prune, that is, to add an extra instance to construction 2, the same as the $D_4$ invariants, and to add an extra instance to construction 3, which appears in construction 1; (2) you can identify these seven examples with the seven reflection groups in $GL_2(\mathbb Z)$ by saying that the ring of invariants is a localization of the lambda-ring. But that isn't a construction, so you still need all three constructions. | |
| Nov 9, 2012 at 22:30 | history | answered | Will Sawin | CC BY-SA 3.0 |