Cluster physics with dark energy

摘要

Dark energy affects the abundance and evolution of clusters owing to their dependence on the geometry of the Universe and the power spectrum. Usually, there exits the degeneracy between σ_8 and the matter energy density contrast Ω rm m}0. We avoid this by using the explicit dark energy dependent rms linear mass fluctuation σ_8 which is consistent with the CMB normalization for general constant dark energy equation of state, ω_Q. When we use the correct value of the critical density threshold δ_c = 1.58 into the cluster number density n calculation in the PressSchechter (PS) formalism, PS formalism predicts the cluster number consistent with both simulation and observed data at the high mass region. The improved coefficients of ShethTormen (ST) formalism by using the correct δ_c is also obtained. We found that changing ω_Q by ω_Q =-0.1 from ω_Q =-1.0 causes the changing of the comoving numbers of high mass clusters of M = 10 ~(16)h~(-1)M⊙ by about 20 and 40% at z = 0 and 1, respectively.