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, ²D, ³He, ⁴He, ⁷Li, 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-to-photon density ratio, and Ω 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 Ω 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.