We investigate an extension of the \Lambda CDM model where the dark matter ( DM ) is coupled to photons , inducing a nonconservation of the numbers of particles for both species , where the DM particles are allowed to dilute throughout the cosmic history with a small deviation from the standard evolution decaying into photons , while the associated scattering processes are assumed to be negligible .
In addition , we consider the presence of massive neutrinos with the effective number of species N _ { eff } as a free parameter .
The effects of the DM-photon coupling on the cosmic microwave background ( CMB ) and matter power spectra are analyzed .
We derive the observational constraints on the model parameters by using the data from CMB , baryonic acoustic oscillation ( BAO ) measurements , the recently measured new local value of the Hubble constant from the Hubble Space Telescope , and large scale structure ( LSS ) information from the abundance of galaxy clusters .
The DM-photon coupling parameter \Gamma _ { \gamma } is constrained to \Gamma _ { \gamma } \leq 1.3 \times 10 ^ { -5 } ( at 95 % C.L . )
from the joint analysis carried out by using all the mentioned data sets .
The neutrino mass scale \sum m _ { \nu } upper bounds at 95 % C.L .
are obtained as \sum m _ { \nu } \sim 0.9 eV and \sum m _ { \nu } \sim 0.4 eV with and without the LSS data , respectively .
We observe that the DM-photon coupling cause significant changes in the best fit value of N _ { eff } but yields statistical ranges of N _ { eff } compatible with the standard predictions , and we do not find any evidence of dark radiation .
Due to nonconservation of photons in our model , we also evaluate and analyze the effects on the BAO acoustic scale at the drag epoch .
The DM-photon coupling model yields high values of Hubble constant consistent with the local measurement , and thus alleviates the tension on this parameter .