Stellar electron-capture rates calculated with the finite-temperature relativistic random-phase approximation

We introduce a self-consistent microscopic theoretical framework for modeling the process of electron capture on nuclei in stellar environment, based on relativistic energy density functionals. The finite-temperature relativistic mean-field model is used to calculate the single-nucleon basis and the occupation factors in a target nucleus, and J(pi) = 0(+/-), 1(+/-), and 2(+/-) charge-exchange transitions are described by the self-consistent finite-temperature relativistic random-phase approximation. Cross sections and rates are calculated for electron capture on Fe-54,Fe-56 and Ge-76,Ge-78 in stellar environment, and results compared with predictions of similar and complementary model calculations.