Primordial nucleosynthesis including radiative, Coulomb, and finite-temperature corrections to weak rates

We calculate the changes in the yields of primordial nucleosynthesis which result from small corrections to rates for weak processes that connect neutrons and protons. We correct the weak rates by improved treatment of Coulomb and radiative corrections, and by inclusion of plasma effects. Our calculations lead to a systematic decrease in the predicted /sup 4/He abundance of about ..delta..Y = 0.0025. The relative changes in other primordial abundances are also 1--2 %.