prochet
|
Registered User
|
|
|
15h |
comment |
Smooth map to the stack of G-bundles very enlightening thank you! |
|
1d |
asked | lift elements in affine singular variety. |
|
2d |
comment |
descent for formally smooth maps In the infinitesimal lifting property, can we reduce to easier rings, such local henselian or local for example? |
|
Jun 16 |
asked | descent for formally smooth maps |
|
Jun 14 |
comment |
Smooth map to the stack of G-bundles In my case, $Bun_{B,r}$ corresponds to the open substack obtained by base change from the analog open substack $\Bun_{T,r}$ consisting of $T$-torsors E such that $H^{1}(X,E\times^{T}V)=0$ for any representation $V$ of $T$ which appear as subquotients of $Lie(U^{-})$ where $U^{-}$ is the opposite unipotent radical of $B$ |
|
Jun 13 |
comment |
Smooth map to the stack of G-bundles I don't understand the purpose of the lemma 14.2.1 then, why restricting to an open subset if everything is already smooth with connected fibers? |
|
Jun 12 |
asked | Smooth map to the stack of G-bundles |
|
Jun 12 |
comment |
differential of the characteristic polynomial For example if $F=k((\pi))$ and $\mathcal{O}=k[[\pi]]$ do we have that for $n$ big enough an section $h\in\mathfrak{g}(X-x)$ such that: $d\chi_{\gamma}(h)=\pi^{-n}\mathcal{O}^{*}+Q(\pi^{-1})$ with $Q$ a polynomial of degree less than n-1? |
|
Jun 12 |
comment |
differential of the characteristic polynomial $k$ an algebraically closed field. |
|
Jun 12 |
comment |
differential of the characteristic polynomial the motivation is the following: Let $F$ a local field at a closed point $x$ of a smooth projective curve $X$ over $k$ (completion of function field at the place $x$). I take $\gamma\in G(F)$ regular semsisimple, we then have a map $d\chi_{\gamma}:\mathfrak{g}(F)\rightarrow \mathbb{A}^{r}(F)$ my question is to try to characterize the image of $d\chi_{\gamma}(\mathfrak{g}(X-x))$ where $\mathfrak{g}(X-x)$ denotes the section of $\mathfrak{g}$ with values in $X-x$. |
|
Jun 11 |
asked | differential of the characteristic polynomial |
|
Jun 8 |
comment |
Galois cohomology of the field of Laurent series or at least do we have that any $T$-torsor on $k((t))$ is trivial? As a matter of fact I think that $k((t))$ is of cohomological dimension one only if $k$ is algebraically closed. |
|
Jun 8 |
asked | Galois cohomology of the field of Laurent series |
|
Jun 8 |
comment |
closed subscheme of ind scheme yes, that's right. |
|
Jun 8 |
comment |
closed subscheme of ind scheme maybe we also need to assume that $X$ is a indscheme over a countable set. |
|
Jun 8 |
asked | closed subscheme of ind scheme |
|
Jun 6 |
asked | open immersion, affine grassmanian and negative loop group |
|
May 29 |
asked | etale cohomology of an abelian variety and its dual |
|
May 25 |
asked | open immersion between affine spaces |
|
May 19 |
asked | affine schubert cells and bruhat order |
|
May 17 |
asked | affine weyl group and affine schubert cells |
|
May 14 |
comment |
weights and exceptional root systems thanks a lot for your detailed answer. |
|
May 13 |
comment |
weights and exceptional root systems It doesn't always hold, because in case $D_{n}$ it never holds, but maybe there is sth that I don't understand in your answer? |
|
May 13 |
asked | weights and exceptional root systems |
|
May 13 |
awarded | ● Supporter |
|
May 10 |
comment |
solve the singularities of parabolic orbits of schubert cells yes but a resolution of singularities of $\overline{BwP}$ is birational on $BwP$ and not on $PwP$ a priori |
|
May 10 |
asked | solve the singularities of parabolic orbits of schubert cells |
|
May 7 |
comment |
quasi-minuscule representations And for these representations, what is the characteristic polynomial? More generally where can we find the polynomial invariants for exceptional groups? |
|
May 7 |
comment |
quasi-minuscule representations yes but we don't know to which highest weight they correspond. |
|
May 7 |
asked | quasi-minuscule representations |
|
May 6 |
comment |
group generated by Coxeter elements How do we know that they generate a normal subgroup? And for $C_{2n+1}$ or $B_{2n+1}$ do we still obtain W? |
|
May 5 |
asked | group generated by Coxeter elements |
|
Apr 16 |
comment |
The intersection complex and the Cohen-Macaulay property d is the codimension, IC is the intersection complex. |
|
Apr 15 |
comment |
The intersection complex and the Cohen-Macaulay property Let assume also that both X and Y are equidimensionnal, and that a resolution of singularities for X gives by base change a resolution of singularities for Y. |
|
Apr 15 |
asked | The intersection complex and the Cohen-Macaulay property |
|
Apr 14 |
asked | on flat morphisms |
|
Apr 13 |
asked | on rational singularities |
|
Apr 12 |
asked | semicontinuity results for weights |
|
Apr 6 |
comment |
sections of vector bundles transversal to a divisor I mean that for a point $x\in X$ and $s$ a section of $E$, either $x\in S$ and the $s(x)\notin D$, either $x\in X-S$ and then s(x) needs to meet transversally $D$. |
|
Apr 4 |
asked | sections of vector bundles transversal to a divisor |
|
Mar 20 |
asked | on geometric Satake and functions |
|
Feb 19 |
asked | on degree zero elements in adelic groups |
|
Feb 14 |
asked | on z-extensions |
|
Feb 13 |
comment |
sections of vector bundles Yes I shouldn't have formulate like this. In fact, I only need the proposition for $V'\subset V$ two vector spaces such that $E$ (resp E') are the trivial vector bundles of fibres V and V' |
|
Feb 13 |
asked | sections of vector bundles |
|
Feb 9 |
comment |
minuscule representations and classical groups I stated for classical groups to make the statement easier, because although $E_{6}$ and $E_{7}$ have minuscule weights, $E_{8}$ $F_{4}$ and $G_{2}$ don't. Moreover, I know that groups don't have to be simply connected to have minuscule weights or coweights, because in my comment I took the example of $GL_{n}$. Nevertheless, if I take $SL_{n}$ for example, it doesn't have minuscule coweights, so my question was, is it possible to have a $z$-extension of $SL_{n}$, for example, that admits minuscule coweights. |
|
Feb 8 |
comment |
on trivialisation of T-torsors $x$ is a closed point on the curve |
|
Feb 8 |
comment |
minuscule representations and classical groups and in fact, my question is rather for minuscule coweights, |
|
Feb 8 |
comment |
minuscule representations and classical groups the comment is in two part, the example is to answer your second question. I used classical types, because we now that in each type, the simply connected group associated to it has at least one minuscule representations. For exceptional type, a group of type $G_{2}$ doesn't have minuscule representations. |
|
Feb 8 |
comment |
minuscule representations and classical groups I restrict for classical groups, because for exceptional types, there is not minuscule weights. For instance, if I take $PGL_{n}$ there is no minuscule irréducible representations, but for $GL_{n}$ yes |

