14.1. The Hodge Operators
What are Maxwell’s equations in a curved space-time?
14.1a. The Operator
On a (pseudo-)Riemannian manifold Mn we introduce a pointwise scalar product between p-forms by
where, as usual, I = (i1,…, ip), and denotes that in the implied sum we have i1 < i2 < … < ip .It is not difficult ...