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visits | member for | 3 years, 4 months |
seen | 21 hours ago | |
stats | profile views | 765 |
Jan 31 |
comment |
Basics on anabelian geometry and Grothendieck's section conjecture
seems very redundant with mathoverflow.net/questions/108860/… to me. |
Jan 24 |
comment |
linearly reductive group acting on $X$
Then, this holds. You just derive the formula for $i=0$ using (for instance) Grothendieck's spectral sequence for the derived functors of a composite functor, and the fact that $(\cdot)^G$ is exact. There is an elementary direct proof of course. |
Jan 24 |
comment |
another question on the Manin-Drinfeld theorem
You could have a look at the book Modular Units Daniel S. Kubert, Serge Lang specifically the chapter The Cuspidal Divisor Class Group on X(N) Good luck ! |
Jan 24 |
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linearly reductive group acting on $X$
What are $\mathcal{F}$,$\mathcal{G}$ ? |
Jan 10 |
answered | Spin group as an automorphism group |
Dec 21 |
comment |
What is your picture of the flat topology?
"don't forget to buy my products" means "vote for my answer" ? |
Dec 19 |
awarded | Yearling |
Dec 2 |
comment |
homotopy exact sequence for the étale fundamental group
In my opinion this part of SGA1 does need no translation, it is perfectly clear. |
Dec 1 |
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homotopy exact sequence for the étale fundamental group
basically it is way too involved in my opinion. I would suggest to have a look at SGA1 which I find much more clear. |
Nov 25 |
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homotopy exact sequence for the étale fundamental group
will all respect, this is very explicit, but this is not very understandable ... |
Nov 16 |
answered | Group action on a stack and fixed points |
Nov 11 |
comment |
Classifying spaces of algebraic groups
hint : this is the pull-back of the universal $BG_m$ torsor via $Bdet: BGL_r\to BG_m$. |
Oct 17 |
revised |
Explicit description of the stack associated to a groupoid
edited body |
Oct 16 |
answered | Explicit description of the stack associated to a groupoid |
Sep 2 |
comment |
alternate interpretations of Galois action on Tate module
the action you define is clearly independent of the section, so your question has little to do with sections. |
Sep 2 |
comment |
alternate interpretations of Galois action on Tate module
You probably mean "we get an action $\rho_{\ell} : \pi_{1}(\mathrm{Spec}(K)) \to \mathrm{Aut}(T_{\ell}(E))$". |
Jun 25 |
awarded | ag.algebraic-geometry |
Apr 17 |
comment |
Adjunction Formula for Weil Divisors on a Normal Variety X
What is a Devisor ? |
Mar 10 |
comment |
what is Deligne's cohomological descent (and what are some examples)
Luc Illusie "La descente galoisienne", Moscow Math. Journal 9-1 (2009), 47-55. math.u-psud.fr/~illusie/Deligne_I3.pdf |
Mar 9 |
comment |
How to see the geometry and arithmetic of tannakian fundamental groups?
My comment is just the way Deligne justifies the introduction of tannakian fundamental groups. In your own answer the topological fundamental group does not appear which makes a difference, don't you agree ? Moreover you did not reply to my question: what means fundamental group in occurrences 3, 4, 5 of your answer ? |