团簇形成时间的概率分布和隐含Einstein半径
The probability distribution of cluster formation times and implied Einstein Radii
摘要：
我们提供了一个定量评估的概率分布函数的浓度参数的星系团。我们这样做，通过使用的概率分布函数的晕形成时间，计算的偏移集形式主义，和形成红移浓度缩放来自N体模拟的结果。我们的研究结果表明，观察到的高浓度的几个集群是不太可能在标准的Lambda CDM宇宙学模型，但由于各种固有的不确定性，预测的分布的统计范围可能会显着更广泛的比公认的。此外，还计算了A1689的爱因斯坦半径的概率分布函数，证实了在目前流行的宇宙学模型中，~45”+/- 5”的观测值是非常不可能的。然而，如果假设维里半径的理论预测值的方差约为20%，则这种差异要弱得多。在其他几个星系团中测量同样大的爱因斯坦半径会给标准模型带来困难。如果是这样的话，那么就需要更早形成大尺度结构，这与某些精粹模型的预测是一致的。我们确实已经证实，在一个可行的早期暗能量模型中，大爱因斯坦半径被预测在多达几十个高质量星系团中。
英文摘要：
We provide a quantitative assessment of the probability distribution function of the concentration parameter of galaxy clusters. We do so by using the probability distribution function of halo formation times, calculated by means of the excursion set formalism, and a formation redshift-concentration scaling derived from results of N-body simulations. Our results suggest that the observed high concentrations of several clusters are quite unlikely in the standard Lambda CDM cosmological model, but that due to various inherent uncertainties, the statistical range of the predicted distribution may be significantly wider than commonly acknowledged. In addition, the probability distribution function of the Einstein radius of A1689 is evaluated, confirming that the observed value of ~45" +/- 5" is very improbable in the currently favoured cosmological model. If, however, a variance of ~20% in the theoretically predicted value of the virial radius is assumed, than the discrepancy is much weaker. The measurement of similarly large Einstein radii in several other clusters would pose a difficulty to the standard model. If so, earlier formation of the large scale structure would be required, in accord with predictions of some quintessence models. We have indeed verified that in a viable early dark energy model large Einstein radii are predicted in as many as a few tens of high-mass clusters.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
