I am having trouble getting my head around several of the concepts related to the very early activities of the universe expansion. For this thread in particular, what are the assumptions regarding the relative number of particles of different species before and after annihilation. First, I am aware that the nucleon antinucleon annihilation occurred much before the electron positron annihilation. 1. Was is the assumed ratio rp of the number of per unit volume (PUV) of protons before to after their annihilation with antiprotons? 2. Was is the assumed ratio re of the number of PUV of electrons before to after their annihilation with positrons? I am concluding that there must be an assumed value for this 2nd ratio because of the calculation of the temperature difference between photons and neutrinos. The temperature difference would be the difference in average kinetic energy of the various particles in equilibrium with the photons due to the energy released by the annihilation. I am assuming that the number npa of protons PUV after annihilation is the same as the number nea of electrons PUV after annihilation, because the net charge of the universe is supposed to be zero. However, these two values before annihilation, npb and neb, need not necessarily be the same. If rp = rethen npb = neb. 3. If these equalities are assumed to hold, what is the justification for this assumption?