Two-loop QED corrections with closed fermion loops for the bound-electron g factor

Abstract

Two-loop QED corrections with closed fermion loops are calculated for the 1s bound-electron g factor. Calculations are performed to all orders in the nuclear binding strength parameter Zα(where Z is the nuclear charge and αis the fine structure constant) except for the closed fermion loop, which is treated within the free-loop (Uehling) approximation in some cases. Comparison with previous Zα-expansion calculations is made and the higher-order remainder of order α^2(Zα)^5 and higher is separated out from the numerical results.