p-form electrodynamics
In theoretical physics, p-form electrodynamics is a generalization of Maxwell's theory of electromagnetism.
Ordinary (via. one-form) Abelian electrodynamics
We have a one-form , a
where is any arbitrary fixed
where is the Hodge star operator.
Alternatively, we may express as a closed (n − 1)-form, but we do not consider that case here.
is a
satisfies the equation of motion
(this equation obviously implies the continuity equation).
This can be derived from the action
where is the spacetime manifold.
p-form Abelian electrodynamics
We have a p-form , a
where is any arbitrary fixed (p − 1)-form and is the
where is the Hodge star operator.
Alternatively, we may express as a closed (n − p)-form.
is a
satisfies the equation of motion
(this equation obviously implies the continuity equation).
This can be derived from the action
where M is the
Other sign conventions do exist.
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 11-dimensional supergravity or M-theory, we have a 3-form electrodynamics.
Non-abelian generalization
Just as we have non-abelian generalizations of electrodynamics, leading to Yang–Mills theories, we also have nonabelian generalizations of p-form electrodynamics. They typically require the use of gerbes.
References
- Henneaux; Teitelboim (1986), "p-Form electrodynamics", Foundations of Physics 16 (7): 593-617,
- Bunster, C.; Henneaux, M. (2011). "Action for twisted self-duality". Physical Review D. 83 (12): 125015. S2CID 119268081.
- Navarro; Sancho (2012), "Energy and electromagnetism of a differential k-form ", J. Math. Phys. 53, 102501 (2012)