Skip to main content
9 events
when toggle format what by license comment
Jul 26, 2016 at 10:56 comment added Saal Hardali @DavidBen-Zvi (Medium to High enthusiasm:) Is the monad in your statement the one you get from the composition of the push/pull (with some possible shrieks) adjunctions $BG \leftarrow BB \rightarrow BH$? (Very High enthsiasm) : "identification of that monad as a graded version of the Weyl group" Where can I find more about this?! I tried googling "Sam Gunningham" along with other stuff and nothing turned up. Finally I must confess I'm a die hard fan of yours, I can't thank you enough for all your insightful comments and answers on this site!
Jul 24, 2016 at 1:10 comment added David Ben-Zvi Here and elsewhere W appears in the form of B\G/B, the self fiber product of BB over BG. BTW this formulation of BWB I learned from Sam Gunningham's thesis
Jul 24, 2016 at 1:07 comment added David Ben-Zvi Here H= the torus, which you shouldn't consider as a subgroup of G but via the correspondence G <-- B --> H for B a Borel
Jul 24, 2016 at 1:04 comment added David Ben-Zvi Yes Borel Weil Bott can be rewritten as the description of sheaves on BG as modules for a monad on BH, and the identification of that monad as a graded version of the Weyl group
Jul 23, 2016 at 21:15 comment added Saal Hardali So is there a phrasing of Borel-Weil-Bott which says something like "the derived pushforward on coherent sheaves from $Coh((G/H)/G)$ to $Coh(pt/G)$ decsends to an equivalence of grothendiek groups or something similar in vane? (maybe weaker or stronger).
Jul 23, 2016 at 21:11 history edited Qiaochu Yuan CC BY-SA 3.0
added 26 characters in body
Jul 23, 2016 at 21:09 comment added Qiaochu Yuan @Saal: yes. It makes more sense if I write the quotient by $G$ on the left but I've forgotten how to do that in LaTeX.
Jul 23, 2016 at 21:03 comment added Saal Hardali This is great stuff thanks! So the equivalence of stacks between $(G/H)/G$ and $pt/H$ is purely formal?
Jul 21, 2016 at 18:21 history answered Qiaochu Yuan CC BY-SA 3.0