Hi!(adsbygoogle = window.adsbygoogle || []).push({});

The Dirac delta satisfies

[tex]\int dx f(x) \delta(x-a) = f(a)[/tex]

But how about

[tex]\int d^3x f(x) \delta^{(4)}(x-a)[/tex]

Here, x and a are four-momenta, and the integral is over the regular 3-dim momentum.

How does the delta behave here?

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Integration of Dirac delta w/ different dimensionalities

**Physics Forums | Science Articles, Homework Help, Discussion**