CνB Damping of Primordial Gravitational Waves and the Fine-Tuning of the CγB Temperature Anisotropy

Figure 3

Evolution of the normalized wave amplitude as function of for the RMD scenario in case of including the collision terms. Results are for , and and for the collisionless case. is given in units of and in units of . We have considered three neutrino species with (red lines) and the extreme case of a huge number of neutrino species with (black lines). The RMD curves are correctly interpreted by observing that (see also Figure 8 for comparison).