CMB constraints

Overview

The Theory class contains functions for computing CMB limits and \(f_{\mathrm{eff}}\) for dark matter models. Other useful constants and functions are also available.

Computing CMB limits

Functions and constants

hazma.cmb.p_ann_planck_temp_pol = 3.5e-31

Planck 2018 95% upper limit on p_ann from temperature + polarization measurements, in cm^3 s^-1 MeV^-1

hazma.cmb.p_ann_planck_temp_pol_lensing = 3.3e-31

Planck 2018 95% upper limit on p_ann from temperature + polarization + lensing measurements, in cm^3 s^-1 MeV^-1

hazma.cmb.p_ann_planck_temp_pol_lensing_bao = 3.2e-31

Planck 2018 95% upper limit on p_ann from temperature + polarization + lensing + BAO measurements, in cm^3 s^-1 MeV^-1

hazma.cmb.vx_cmb(mx, x_kd)

Computes the DM relative velocity at CMB using eq. 28 from this reference.

Parameters

• mx (float) – Dark matter mass in MeV.

• x_kd (float) – T_kd / m_x, where T_kd is the dark matter’s kinetic decoupling temperature.

Returns

v_x – The DM relative velocity at the time of CMB formation.

Return type

float