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Zhaoting Wei's user avatar
Zhaoting Wei's user avatar
Zhaoting Wei's user avatar
Zhaoting Wei
  • Member for 12 years, 5 months
  • Last seen this week
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Beilinson-Bernstein localization: $\mathfrak{g}$ action on $G$-equivariant sheaf
I'm not an expert but I feel that a more comfortable definition for me is to let $i: X\rightarrow G\times X$ by $x\mapsto (e,x)$ and define the action by $\Phi(a)s=i^*[(a\otimes 1)\cdot \phi^{-1}(\sigma^*s)]$. This illustrate the idea of "infinitesimal action of $a$".
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When do we have $D_{\text{perf}}(\text{Qcoh}(X))\simeq D_{\text{perf}}(X)$?
@Adeel Yes, that's obviously my mistake. After reading your comment now I believe that maybe quasi-compact and quasi-separated is the best I can expect.
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An alternative definition of pseudo-coherent complex
The Noetherian condition can be loosened to be locally Noetherian, isn't it?
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An alternative definition of pseudo-coherent complex
Does my definition itself stand for other types of complexes?
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An alternative definition of pseudo-coherent complex
@bananastack Yes. Actually for each $m$ we can take $\bigoplus_{0\leq i\leq -m}$ to be our strictly perfect complex in part one of the definition.
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What kind of ringed space $X$ has the property that a locally free sheaf is projective in Qcoh$(X)$?
@FernandoMuro Yes smooth manifolds with the sheaf of smooth functions gives an affirmative example. However I'm looking for a more general criterion. For example, complex manifold in general does not satisfy my requirement. Only Stein manifolds work here. So I wonder what is the general condition here. I believe it's some cohomological requirement but I'm not sure.
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How to prove that any perfect complex on an affine scheme is strictly perfect?
@FernandoMuro Maybe that's not true, at least not so obvious, since for open set $U$, $V$, the complex of free sheaves $\mathcal{E}^{\bullet}_U$ and $\mathcal{E}^{\bullet}_V$ are quite different. Indeed they are quasi-isomorphic on $U\cap V$ but this does not guarantee that they glue together into a complex of locally free sheaves on $U\cup V$.
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How to prove that any perfect complex on an affine scheme is strictly perfect?
Thank you for pointing out! That is a typo and I have made correction in the definition of strictly perfect complex.
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How to prove that any perfect complex on an affine scheme is strictly perfect?
In the definition of strictly perfect complex, "free sheaves" has been replaced by "locally free sheaves".
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