darkhistory.physics.CMB_spec¶
- darkhistory.physics.CMB_spec(eng, temp)¶
CMB spectrum in number of photons cm-3 eV-1.
The normalization used here is
\[\begin{split}\\frac{dN}{dE \\, dV} = \\frac{E^2}{\\pi^2 (\\hbar c)^3} \\frac{1}{e^{E/T_\\text{CMB}} - 1} \\,,\end{split}\]with TCMB given in eV. Returns zero if E > 500 TCMB.
- Parameters:
- tempfloat
Temperature of the CMB in eV.
- engfloat or ndarray
Energy of the photon in eV.
- Returns:
- ndarray
The number density of photons per unit energy in eV.