- #1
rubenvb
- 9
- 0
double integral to single by "magic" substitution
Hi,
I have a double (actually quadruple, but the other dimensions don't matter here) integral which looks like this:
[tex] \iint_0^\infty \frac{d^2 k}{k^2} [/tex]
Now, someone here told me to replace that with
[tex] \int_0^\infty \frac{1}{2} 2\pi \frac{d k^2}{k^2} [/tex]
How and why is this ok? Thanks!
PS: For anyone wondering where this comes up: it's related to Elementary Particle physics and structure function calculation.
Hi,
I have a double (actually quadruple, but the other dimensions don't matter here) integral which looks like this:
[tex] \iint_0^\infty \frac{d^2 k}{k^2} [/tex]
Now, someone here told me to replace that with
[tex] \int_0^\infty \frac{1}{2} 2\pi \frac{d k^2}{k^2} [/tex]
How and why is this ok? Thanks!
PS: For anyone wondering where this comes up: it's related to Elementary Particle physics and structure function calculation.