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Timeline for a question about Beauville-Laszlo

Current License: CC BY-SA 3.0

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Feb 25, 2013 at 12:30 comment added user28172 In the noetherian case, BL is a special case of usual faithfully flat descent. For any noetherian ring $R$ (such as $V[[u,v]]/(uv-\pi)$) and any $\pi \in R$, an element of $R$ divisible by $\pi$ in the $\pi$-adic completion $R'$ of $R$ is divisible by $\pi$ in $R$ because the natural map $R/\pi R \rightarrow R'/\pi R'$ is injective (even an isomorphism), and the diagonal map $R \rightarrow R[1/\pi] \times R'$ is injective (by faithful flatness considerations locally along the zeros of $\pi$ in Spec($R$)), so the $F$ you ask about is always the original noetherian ring $R$.
Feb 25, 2013 at 11:00 history edited questio CC BY-SA 3.0
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Feb 25, 2013 at 9:05 history asked questio CC BY-SA 3.0