Differentials over Differential Fields
نویسنده
چکیده
Given an algebraA over a differential fieldK, we study derivations on A that are compatible with the derivation on K. There is a universal object, which is a twisted version of the usual module of differentials, and we establish some of its basic properties. In the context of differential algebraic geometry, one gets a sheaf of these τ -differentials which can be interpreted as certain natural functions on the prolongation of a variety, as studied by Buium. This sheaf corresponds to the Kodaira-Spencer class of the variety.
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