  The Sommerfeld enhancement plays an important role in dark matter (DM)
physics, and can significantly enhance the annihilation cross section of
non-relativistic DM particles. In this paper, we study the effect of neutrino
forces, which are generated by the exchange of a pair of light neutrinos, on
the Sommerfeld enhancement. We demonstrate that in certain cases, a neutrino
force can cause a significant correction to the Sommerfeld enhancement. Models
that can realise DM-neutrino interactions and sizeable Sommerfeld enhancement
are also briefly discussed, together with the impacts on DM phenomenology of
neutrino forces.
