Skip to main content
5 events
when toggle format what by license comment
Apr 22, 2016 at 19:57 comment added Georges Elencwajg @user54268: sorry, I don't understand your comment. How do you define $R$ and what do you pull-back over $R$ ?
Aug 17, 2014 at 0:17 vote accept Li Yutong
Aug 16, 2014 at 14:39 comment added user54268 Technically, as you know, the crucial thing is that for any noetherian scheme $B$ and distinct points $s, \eta \in B$ with $s \in \overline{\{\eta\}}$, there exists a map ${\rm{Spec}}(R) \rightarrow B$ for a dvr $R$ such that the closed point goes to $s$ and the generic point goes to $\eta$. Pullback over $R$ encodes these two fibers at the cost of a huge extension of their residue fields (especially at $s$). So for issues about geometric fibers, base as dvr captures a lot. And of course flatness is easy to control over a dvr (such as for schematic closures from the generic fiber, etc.).
Aug 16, 2014 at 14:33 history made wiki Post Made Community Wiki by Donu Arapura
Aug 16, 2014 at 14:19 history answered Donu Arapura CC BY-SA 3.0