Effective description of dark matter self-interactions in small dark matter haloes

摘要: Self-interacting dark matter may have striking astrophysical signatures, such as observable offsets between galaxies and in merging galaxy clusters. Numerical N-body simulations used to predict observables typically treat the collisionless test particles, a questionable assumption given that each is embedded its own halo. To enable more accurate treatment we develop an effective description of small haloes taking into account two major effects due self-scatterings: deceleration evaporation. We point out self-scatterings can sizeable impact on trajectories galaxies, diminishing separation This effect depends sensitively underlying particle physics, particular angular dependence self-scattering cross section, cannot be predicted from momentum transfer section alone.