Constraints on dark matter annihilation and its equation of state after Planck data

Abstract

In this paper, the annihilation of dark matter (DM) f_dɛ₀ with nonzero equation of state (EoS) w_dm was studied by using the currently available cosmic observations which include geometric and dynamic measurements. The constrained results show they are anti-correlated and are w dm = 0.000390_-0.000753^+0.000754 and f_{d&epsilon_0;} = 1.172_-1.172^+0.243, respectively in 1σ regions. With the inclusion of possible annihilation of DM, no significant deviation from ΛCDM model was found in the 1σ region.