[Tex/LaTex] Correct symbol for the Laplace operator ($\Delta$)


What is the correct symbol to use for the Laplace operator? It looks almost like the big Delta $\Delta$, but it should look different so that it is not confused with the Delta.

Currently, I use $\vec \nabla^2$, which is unambiguous, but not pretty.

Best Answer

If you use the D'Alembert operator as well, you might find pretty using the symbol \bigtriangleup for your Laplace operator, in order to get a similar look as the \Box symbol that is being used for D'Alambertian. In the following, a tricky construction with \mathop and \mathbin is used to get the proper spacing:






  \phi(1+\Laplace A) \neq \phi(1+\Delta A)
  \phi(1+\DAlambert A) \neq \phi(1+\Laplace A)
  f\Laplace g