In theoretical physics, p-form electrodynamics is a generalization of Maxwell's theory of electromagnetism.
is the exterior derivative, and a gauge-invariant vector current
with density 1 satisfying the continuity equation where
is the Hodge star operator.
is a gauge-invariant 2-form defined as the exterior derivative
is the exterior derivative, and a gauge-invariant p-vector
with density 1 satisfying the continuity equation where
is a gauge-invariant (p + 1)-form defined as the exterior derivative
This can be derived from the action where M is the spacetime manifold.
The Kalb–Ramond field is an example with p = 2 in string theory; the Ramond–Ramond fields whose charged sources are D-branes are examples for all values of p. In eleven-dimensional supergravity or M-theory, we have a 3-form electrodynamics.
Just as we have non-abelian generalizations of electrodynamics, leading to Yang–Mills theories, we also have nonabelian generalizations of p-form electrodynamics.