# Scalar density integral

1. Sep 27, 2015

### Korbid

hi!

i need to solve this integral:

$\rho_s=\int (m/\omega)e^{-\omega/T}d{\vec k}$
where $\omega=\sqrt{m^2+{\vec k}}$ is the dispersion relation, T is the temperature of the system and m the mass of a particle

Thank you!

2. Sep 27, 2015

### Staff: Mentor

How do you add a scalar to a vector?

If k would be a scalar, the derivative of $e^{-\omega / T}$ looks promising.

3. Sep 28, 2015

### Korbid

Sorry! I was wrong!

$\omega = \sqrt{m^2 + \vec{k}^2}$

However, i still can't solve it.

4. Sep 28, 2015

### Staff: Mentor

Did you try spherical coordinates?