  We study the production of jet-bremsstrahlung photons through the scattering
with the constituents of a dense nuclear matter within the framework of
deep-inelastic scattering off a large nucleus. Applying a gradient expansion up
to the second order for the exchanged three-dimensional momentum between jet
and medium, we derive the single photon bremsstrahlung spectrum with the
inclusion of the contributions from the transverse broadening as well as the
longitudinal drag and diffusion of the hard parton's momentum. We also compare
the medium-induced photon radiation spectra for single scattering and from the
resummation of multiple scatterings. It is found that the coupling between
different scatterings can give additional contribution to medium-induced photon
radiation, while for small momentum exchange, the leading contribution from the
drag and diffusions to the photon emission spectra remain the same for single
and multiple scatterings.
