Effects of Possible Deviations of Fundamental Physical Constants on Primordial Nucleosynthesis

We study the effects of possible deviations of fundamental physical constants on the yields of light nuclides, 2 D, 3 He, 4 He, 7 Li , and others during primordial nucleosynthesis. The deviations of fundamental constants from their current values are considered in the low-energy approximation of string theories; the latter predict the existence of a scalar field, which, apart from the tensor gravitational field, determines the space geometry. A two-parameter ( η , δ ) model is constructed for primordial nucleosynthesis: η = n B / n γ is the baryon-tophoton density ratio, and δ is the relative deviation of fundamental physical constants at the epoch of primordial nucleosynthesis from their current values. A dependence of η on the deviation of coupling constants δ has been derived on condition that the primordial helium abundance is Y p = f ( η , δ ) = const, where const corresponds to experimental values. We thus showed that the relative baryonic density (and hence Ω B ) could vary over a much wider range than allowed by the standard nucleosynthesis model. Considering this result, we discuss the recently found mismatch between Ω B obtained from an analysis of CMBR anisotropy and from the standard primordial nucleosynthesis model. © 2001 MAIK “Nauka/Interperiodica”.