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Jul 22, 2014 at 10:04 vote accept aglearner
Jul 21, 2014 at 20:14 answer added David E Speyer timeline score: 5
Jul 21, 2014 at 15:46 comment added aglearner abx, yes thank you, I understand (I added one more tag - combinatorics). I ask this question here because for the moment I can not answer this combinatorial question.
Jul 21, 2014 at 15:44 history edited aglearner
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Jul 21, 2014 at 15:34 comment added abx As hinted in the previous comments, this is a purely combinatorial problem. We have $H^*(F_n,\mathbb{Q})=\mathbb{Q}[t_1,\ldots ,t_n]/(s_1,\ldots ,s_n)$, where the $t_i$'s are the first Chern classes of the successive tautological quotient line bundles and $s_i$ is the $i$-th symmetric function. The question is to find the order of nilpotence of $t_1(t_1+t_2)\ldots (t_1+\ldots +t_{n-1})$ in that ring (and same question with the last factor deleted).
Jul 21, 2014 at 15:15 comment added aglearner No Peter, I am interested in classes $\sigma_i$. If one replaces $\sigma_i$ by $\sigma_i-\sigma_{i-1}$ as you suggest, the question becomes completely different (and easy to answer)
Jul 21, 2014 at 15:11 comment added Peter Crooks I think you should be taking the first Chern classes of the duals of quotients of adjacent bundles in your flag.
Jul 21, 2014 at 14:45 history asked aglearner CC BY-SA 3.0