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Oct 16, 2010 at 3:17 comment added BCnrd Harry, the general principle underlying Matt's answer is that if $f:X \rightarrow S$ is an flat map of finite type between noetherian schemes then for many interesting "homological" properties $P$ of local noetherian rings the validity of $P$ for $O_{X,x}$ is equivalent to the same for $O_{S,s}$ and $O_{X_s,x}$ together, where $s = f(x)$. This is just a principle rather than a "meta-theorem" (whatever that may mean), but it (or a mild variant) is true for many $P$. Look at the section "flatness and fibers" in Matsumura's "Commutative Ring Theory" for examples (including regularity).
Oct 16, 2010 at 3:05 history edited Emerton CC BY-SA 2.5
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Oct 16, 2010 at 3:02 comment added Hailong Dao Matt, beautiful answer, as usual!
Oct 16, 2010 at 2:54 vote accept Harry Gindi
Oct 16, 2010 at 2:52 history answered Emerton CC BY-SA 2.5