Timeline for Fibers of torus equivariant moment maps
Current License: CC BY-SA 3.0
2 events
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| Nov 21, 2015 at 21:58 | comment | added | Allen Knutson | What one's supposed to do with those fibers is quotient them by $T$, obtaining projective varieties. If you do this at a regular value, the action has finite stabilizers. If you're very lucky, they're trivial, and you have a principal bundle, and the question becomes "which $T$-bundle is this over the quotient", which is answered by its $Lie(T)^*$-valued first Chern class $c$. This was exactly the question Duistermaat-Heckman felt they were answering in "On the Variation in the Cohomology of the Symplectic Form of the Reduced Phase Space"; $c=$ the derivative of $\omega_{red}$ on the base. | |
| Nov 20, 2015 at 22:46 | history | asked | Qiao | CC BY-SA 3.0 |