Derivation: Difference between revisions

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==Definition==
==Definition==


Let <math>R</math> be a [[commutative unital ring]] (resp. [[sheaf of commutative unital rings]]). A derivation of <math>R</math> as a <math>R</math>-module is a map <math>D:  
Let <math>R</math> be a [[commutative unital ring]] (resp. [[sheaf of commutative unital rings]]). A derivation of <math>R</math> is a map <math>D:  
R \to R</math> (resp. a [[sheaf-theoretic map]] from <math>M</math> to itself) such that:
R \to R</math> (resp. a [[sheaf-theoretic map]] from <math>M</math> to itself) such that:



Latest revision as of 19:38, 18 May 2008

Definition

Let be a commutative unital ring (resp. sheaf of commutative unital rings). A derivation of is a map (resp. a sheaf-theoretic map from to itself) such that:

  • is -linear (viz, its a map of -modules)

A derivation on a differential manifold is a derivation on its sheaf of differentiable functions, viewed as a sheaf of commutative unital rings.

Facts

Every vector field on a differential manifold gives rise to a derivation, and this gives a correspondence between vector fields and derivations. For full proof, refer: Vector field equals derivation