Photon number density
= Photon number density
{title2=$n_\gamma$}
In natural units, a thermal photon gas with two polarizations has
$$
n_\gamma=\frac{2\zeta(3)}{\pi^2}T^3.
$$
= Photon number density
{title2=$n_\gamma$}
In natural units, a thermal photon gas with two polarizations has
$$
n_\gamma=\frac{2\zeta(3)}{\pi^2}T^3.
$$