The role of the relativistic amplitudes for a number of O(k)
processes usually neglected in potential model calculations of
NN--bremsstrahlung is investigated. In particular, we consider the
Δ--excitation pole contributions related to the one--pion and one--rho
exchange and in addition include the exchange contributions induced by the
radiative ω,ρ→πγ decays. The contributions are
calculated from relativistic Born amplitudes fitted to Δ--production and
absorption data in the energy range up to 1 GeV and then used to supplement
potential model and soft photon calculations for nucleon--nucleon
bremsstrahlung. The effects on NNγ--observables, although moderate in
general, are found to be important in some kinematic domains.Comment: 15 pages in LaTex, using Revtex, 6 figures as uufile'd, compressed
Postscript file included, TRIUMF preprint TRI-PP-94-9