# Relativistic Invariance Part Two

1. Dec 9, 2003

### Ed Quanta

I am asked to prove that the d'Alembertian operator (the 4 dimensional Laplacian operator) |_|^2 is a lorentz invariant operator. Do I just multiply the Lorentz transformation matrix by the second partial derivatives with respect to four space?

Last edited: Dec 9, 2003
2. Dec 10, 2003

### turin

I suppose you could do that. But I would just show that it is a scalar. Show that it is a contraction of a 1st rank tensor with itself. Use the Minkowski metric tensor to raise the index of one of the partial derivatives and it should be obvious.