contraction
Definition Let be a smooth -form on a smooth manifold ,and let be a smooth vector field on . The contractionof with is the smooth -form that maps to.In other words, ispoint-wise evaluated with in the first slot.We shall denote this -form by .If is a -form, we set for all .
Properties Let and be as above. Thenthe following properties hold:
- 1.
For any real number
- 2.
For vector fields and
- 3.
Contraction is an anti-derivation [1]. If is a -form, and is a -form, then
References
- 1 T. Frankel,Geometry of physics,Cambridge University press,1997.