crystalline differential operator
For a smooth scheme over a field the sheaf of crystalline differential operators is the the “enveloping algebroid of the tangent Lie algebroid” of : to an affine it assigns the algebra that is generated over from the -module of vector fields (derivations of ), subject to the relations
for all and .
If the field has characteristic 0 this is the ordinary sheaf of differential operators
for instance section 3.1 of
- Roman Bezrukavnikov, Noncommutative Counterparts of the Springer Resolution (pdf)
Created on March 30, 2011 07:02:30
by Urs Schreiber