原初连续功率谱宇宙模型下暗物质晕的质量函数

THE MASS FUNCTION OF DARK MATTER HALOES IN A COSMOLOGICAL MODEL WITH A RUNNING PRIMORDIAL POWER SPECTRUM

最近的宇宙学观测结果给出了一个具有原初连续谱功率指数(RSI-CDM)的ΛCDM冷暗物质宇宙模型,而不是标准的尺度无关谱(PL-CDM).基于这个结果,应用半解析近似,对Jenkins et al(J01)质量方程进行了研究,同时在各个连续谱指数暗能量宇宙学模型下计算出这些模型对应的宇宙中最大暗物质晕的位里质量.结果表明,PL-CDM和RSI-CDM宇宙学模型在低红移处有微小差别.与PL-CDM相比,RSI-CDM在低红移处小质量暗晕的质量丰度较大,但在大结构质量晕中两者差别不明显,而且这个差异随着红移降低而增大.RSI-CDM在高红移处压低了任何尺度的暗晕质量丰度.关于最大位里质量,平坦空间ΛCDM宇宙学模型在PL-CDM和RSI-CDM都给出更多大质量天体.因此,对PL-CDM和RSI-CDM功率谱模型,都可以用最大位里质量来区别不同的宇宙学模型.

The recent cosmological observations suggest a ACDM cosmological model with a running spectral power index of primordial density fluctuations. The first study on the mass functions of Jenkins et al （J01） and an estimate of their corresponding largest virialized dark haloes in the universe for a variety of darkenergy cosmological models with a running spectral index is presented. It is shown that there is a slight difference between the power law power spectral（PL）-CDM model and running spectral index （RSI）-CDM model at lower redshifts. Compared with the PL-CDM model, the RSI-CDM model can raise the mass abundance of dark haloes for small mass haloes at lower redshifts, but it is not apparent on scales of massive mass haloes. Particularly, this discrepancy increases largely with the decrease of redshift, and the RSI-CDM model can suppress the mass abundance on any scale of halo masses at higher redshift. As for the largest mass of virialized haloes, the spatially flat ACDM models give more massive mass of virialized objects than other models for both of PL-CDM and RSI-CDM power spectral indexs. Therefore, it can distinguish different cosmological models by the largest mass of virialized haloes for both of PL-CDM and RSI-CDM models. In addition, the RSI-CDM model can enhance the mass of largest virialized haloes for all of models considered in this paper. Thus the PL-CDM and RSI-CDM models are probably distinguished by the largest virialized haloes in the future survey of cluster of galaxies. Therefore, the obtained largest virialized object can be referred to as the complement to the observations of CMB, SN Ia and large scale structure in the future cosmological observations.