Incoming links: Minkowski space
The laplace operator for Minkowski space.
Can be nicely written with Einstein notation as shown at: Section "d'Alembert operator in Einstein notation".
Given the function :the operator can be written in Planck units as:often written without function arguments as:Note how this looks just like the Laplacian in Einstein notation, since the d'Alembert operator is just a generalization of the laplace operator to Minkowski space.
Metric space but where the distance between two distinct points can be zero.
Notable example: Minkowski space.