Skip to main content
7 events
when toggle format what by license comment
Jan 11, 2013 at 3:31 vote accept Serge Lvovski
Jan 10, 2013 at 22:16 history edited inkspot CC BY-SA 3.0
Errors corrected and a query answered
Jan 10, 2013 at 19:04 comment added David Ben-Zvi Also projectivity should not be necessary, the argument you give (and construction of flattening stratification) is local.. maybe Noetherian??
Jan 10, 2013 at 19:04 comment added David Ben-Zvi Note that in characteristic p the statement is false even for X smooth if by $D_X$ you mean the ring of "crystalline diffops" (generated by functions and vector fields), rather than the full divided power ring (whose modules are the same as stratifications) -- eg Frobenius pullback of any coherent sheaf is a D-module.
Jan 10, 2013 at 18:43 comment added Serge Lvovski I am sorry, could you, please, explain in more detail how you conclude that for every $i$ there is a $j$ such that $p_1^{-1}(X_i)=p_2^{-1}(X_j)$?
Jan 10, 2013 at 18:21 comment added David Ben-Zvi This is a very nice argument, but is it clear it applies to D-modules? your definition is that of a stratification (or comodule over jets), which I don't think are the same as modules over the ring of differential operators in general (yours is the much better behaved one in general). I only know they are the same for varieties with only cusp singularities, for which all the various notions of D-module coincide.
Jan 10, 2013 at 18:07 history answered inkspot CC BY-SA 3.0