Possibility of studying the effects of the DM-electron scattering on the cosmic microwave background based on simple assumptions

摘要

Investigating the dark matter (DM) properties in the view of cosmic evolution is an important method in searching for DM. In this paper, we derive the modified Boltzmann equations and study how the elastic scattering between the DM particles and the free electrons in our universe influences the CMB and matter power spectra starting from a few basic assumptions. The results indicates that the scattering affects the small scales significantly, especially the CMB polarization power spectra. With this method, the coupling constant between DM and electrons can be constrained with CMB observational data and the results only depend on a few basic assumptions.