  The relativistic field theory model of the deuteron is applied to the
calculation of the cross sections of the low-energy radiative neutron-proton
capture n + p -> D + gamma and the low-energy two-proton fusion p + p -> D +
e^+ + nu_e. For the low-energy radiative neutron-proton capture n + p -> D +
gamma our result agrees well with both the experimental data and the potential
model prediction. In the case of the two-proton fusion the cross section
obtained is 2.9 times as much as that given by the potential approach. The
obtained result is discussed in connection with the solar neutrino problem.
  ERRATUM: We correct the value of the cross section for pp-fusion p + p -> D +
e^+ + nu_e. We find a contribution to the astrophysical factor \delta S_pp(0) =
2.01 x 10^{-25} (1 +/- 0.30) MeV b which is obtained only due to weak and
strong low-energy interactions of the protons and the deuteron when neglecting
the Coulomb repulsion between protons in the intermediate state. Minor
misprints are corrected.
