CνB Damping of Primordial Gravitational Waves and the Fine-Tuning of the CγB Temperature Anisotropy
Tensor contribution to the angular power spectrum for the RMD scenario in case of including the collision terms. Results are for , and , in units of , and for the collisionless case. Notice that, for decreasing values of the parameter, the suppression due to a huge number of neutrinos (d.o.f.) is not so relevant; that is, the increasing collision effect attenuates the damping effect on the tensor mode propagation and it is reflected on the tensor contribution to the angular power spectrum.