Primordial nucleosynthesis as a probe of fundamental physics parameters

We analyze the effect of variation of fundamental couplings and mass scales on primordial nucleosynthesis in a systematic way. The first step establishes the response of primordial element abundances to the variation of a large number of nuclear physics parameters, including nuclear binding energies. We find a strong influence of the n-p mass difference (for the He-4 abundance), of the nucleon mass (for deuterium), and of A=3, 4, 7 binding energies (for He-3, Li-6, and Li-7). A second step relates the nuclear parameters to the parameters of the standard model of particle physics. The deuterium, and, above all, Li-7 abundances depend strongly on the average light quark mass m boolean AND equivalent to(m(u)+m(d))/2. We calculate the behavior of abundances when variations of fundamental parameters obey relations arising from grand unification. We also discuss the possibility of a substantial shift in the lithium abundance while the deuterium and He-4 abundances are only weakly affected.