“…Similarly the expansion rate can be modified by changing the cosmological equations [37,38], introducing extra energy density in the form of 'Quintessence' [37,39,40,41] and even quite general evolutions have been explored [42]. The effects of new physics from scenarios such as a non-zero electron neutrino chemical potential [43,44,45,46,47,48,49,50] or neutrino oscillations/mass/decay [51,52,53,54,55,56], show up primarily in the neutron-proton interconversion reactions. There the known expressions for these reaction rates permit a high degree of confidence that all the consequences of the new physics have been accurately taken into account.…”