Written in the notation of partial derivatives, the d'Alembertian in a flat spacetime is defined by
where is the speed of light.
The operator usually called the d'Alembertian is also the Laplacian on a flat manifold of Lorentzian signature.
Written in the notation of partial derivatives, the d'Alembertian in a flat spacetime is defined by
where is the speed of light.
The operator usually called the d'Alembertian is also the Laplacian on a flat manifold of Lorentzian signature.
Weisstein, Eric W. "d'Alembertian." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/dAlembertian.html