  We summarize recent ab initio studies of low-energy electroweak reactions of
astrophysical interest, relevant for both big bang nucleosynthesis and solar
neutrino production. The calculational methods include direct integration for
np radiative and pp weak capture, correlated hyperspherical harmonics for
reactions of A=3,4 nuclei, and variational Monte Carlo for A=6,7 nuclei.
Realistic nucleon-nucleon and three-nucleon interactions and consistent current
operators are used as input.
