- #1

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## Main Question or Discussion Point

I was recently told that the integral for a 3-momentum d^3p = 4∏∫p^2 dp

But I dunno what how is this integtal done.

Any help?

But I dunno what how is this integtal done.

Any help?

- Thread starter Ang Han Wei
- Start date

- #1

- 9

- 0

I was recently told that the integral for a 3-momentum d^3p = 4∏∫p^2 dp

But I dunno what how is this integtal done.

Any help?

But I dunno what how is this integtal done.

Any help?

- #2

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[itex]\int dxdydz = \int r^{2}sin(\theta)dr d\theta d\phi[/itex]

if what you're integrating over does not depend on [itex]\theta[/itex] or [itex]\phi[/itex], then you can integrate over those variables giving you an additional factor of [itex]4 \pi[/itex]. Thus

[itex]\int dxdydz = 4\pi \int r^{2}d r[/itex].

I expect d^3p is shorthand for dp_{x}dp_{y}dp_{z}.