标题： 剪切和旋转的约束与大质量星系团 显示英文标题

标题： Constraints on shear and rotation with massive galaxy clusters

摘要： 对质量函数的精确测定是验证宇宙学预测的$\Lambda$冷暗物质模型的重要工具，并且可以更精确地推断描述宇宙演化的更好模型。 目前，星系团已被用于推断宇宙学参数，特别是物质密度参数$\Omega_{\rm m}$，物质功率谱归一化$\sigma_8$以及暗能量流体的状态方程参数$w_{\rm de}$。 在本研究中，利用红移范围为$0.05\lesssim z\lesssim 0.83$的大质量星系团（$M>8\times 10^{14}~h^{-1}~M_{\odot}$）的数据，我们对在扩展球形坍缩模型形式中引入的参数$\alpha$进行了约束，以量化由于剪切和旋转引起的球形度偏差。 由于目前还没有描述其函数形状的物理模型，我们假设它为星系团质量的对数函数。 通过固定$\sigma_8$并将我们的分析限制在$\Lambda$CDM 模型中，我们在$1-\sigma$置信水平上发现，$\Omega_{\rm m}=0.284\pm0.0064$，$h=0.678\pm0.017$和$\beta=0.0019^{+0.0008}_{-0.0015}$，其中$\beta$表示参数$\alpha$的斜率。 这导致与标准$\Lambda$冷暗物质质量函数相比，大质量星系团的数量减少了$9\%$，但需要更好的数据来更精确地限定这一数值，因为在$2-\sigma$和$3-\sigma$置信水平上我们只能推断出上限。 显示英文摘要

摘要： A precise determination of the mass function is an important tool to verify cosmological predictions of the $\Lambda$CDM model and to infer more precisely the better model describing the evolution of the Universe. Galaxy clusters have been currently used to infer cosmological parameters, in particular the matter density parameter $\Omega_{\rm m}$, the matter power spectrum normalization $\sigma_8$ and the equation of state parameter $w_{\rm de}$ of the dark energy fluid. In this work, using data on massive galaxy clusters ($M>8\times 10^{14}~h^{-1}~M_{\odot}$) in the redshift range $0.05\lesssim z\lesssim 0.83$ we put constraints on the parameter $\alpha$ introduced within the formalism of the extended spherical collapse model to quantify deviations from sphericity due to shear and rotation. Since at the moment there is no physical model describing its functional shape, we assume it to be a logarithmic function of the cluster mass. By holding $\sigma_8$ fixed and restricting our analysis to a $\Lambda$CDM model, we find, at $1-\sigma$ confidence level, $\Omega_{\rm m}=0.284\pm0.0064$, $h=0.678\pm0.017$ and $\beta=0.0019^{+0.0008}_{-0.0015}$, where $\beta$ represents the slope of the parameter $\alpha$. This results translates into a $9\%$ decrement of the number of massive clusters with respect to a standard $\Lambda$CDM mass function, but better data are required to better constrain this quantity, since at the $2-\sigma$ and $3-\sigma$ confidence level we are only able to infer upper limits.