On the center of the ring of differential operators on a smooth variety over $\bZ/p^n\bZ$
arXiv:1104.2858 · doi:10.1112/S0010437X12000462
Abstract
We compute the center of the ring of PD differential operators on a smooth variety over $\bZ/p^n\bZ$ confirming a conjecture of Kaledin. More generally, given an associative algebra over $\bF_p$ and its flat deformation over $\bZ/p^{n+1}\bZ$ we prove that under a certain non-degeneracy condition the center of is isomorphic to the ring of length Witt vectors over the center of .
16 pages