根据$H(z)$数据，$Omh^2(z_1,z_2)$和$Om(z_1,z_2)$诊断告诉我们什么？
What are $Omh^2(z_1,z_2)$ and $Om(z_1,z_2)$ diagnostics telling us in light of $H(z)$ data?
摘要：
两点诊断$Om(z_i,z_j)$和$Omh^2(z_i,z_j)$已被引入作为测试$Λ$ CDM模型有效性的有趣工具。最近，Sahni，Shafieloo $\&$ Starobinsky（2014）将来自BAO数据的$H(z)$的两个独立测量值与哈勃常数$H_0$的值结合起来，并使用这些诊断中的第二个来测试$Λ$ CDM模型。他们的结果表明，观测和$Λ$ CDM模型的预测之间存在相当大的张力。由于可靠的数据膨胀率的宇宙在不同的红移$H(z)$是成功应用这种方法的关键，我们调查两个点诊断最全面的一套$N=36$测量的$H(z)$来自BAO和微分年龄（DA）的被动演化星系。我们讨论了两点诊断的不确定性，并发现它们是强非高斯的，并遵循深深植根于其建设的模式。因此，我们建议，非参数中位数统计是最合适的方式来处理这个问题。我们的研究结果支持$Λ$ CDM与$H(z)$数据紧张的说法，根据Shafieloo，Sahni和Starobinsky开发的两点诊断。然而，$Λ$ CDM的其他替代方案，如wCDM或CPL模型，表现甚至更差。我们还注意到，在$H(z)$测量可以与其他探针竞争之前，应该更好地理解BAO和DA方法之间存在严重的系统差异。
英文摘要：
Two-point diagnostics $Om(z_i,z_j)$ and $Omh^2(z_i,z_j)$ have been introduced as an interesting tool for testing the validity of the $Λ$CDM model. Quite recently, Sahni, Shafieloo $\&$ Starobinsky (2014) combined two independent measurements of $H(z)$ from BAO data with the value of the Hubble constant $H_0$, and used the second of these diagnostics to test the $Λ$CDM model. Their result indicated a considerable tension between observations and predictions of the $Λ$CDM model. Since reliable data concerning expansion rates of the Universe at different redshifts $H(z)$ are crucial for the successful application of this method, we investigate both two-point diagnostics on the most comprehensive set of $N=36$ measurements of $H(z)$ coming from the BAO and differential ages (DA) of passively evolving galaxies. We discuss the uncertainties of two-point diagnostics and find that they are strongly non-Gaussian and follow the patterns deeply rooted in their very construction. Therefore we propose that non-parametric median statistics is the most appropriate way of treating this problem. Our results support the claims that $Λ$CDM is in tension with $H(z)$ data according to the two-point diagnostics developed by Shafieloo, Sahni and Starobinsky. However, other alternatives to the $Λ$CDM, such as wCDM or CPL models perform even worse. We also notice that there are serious systematic differences between BAO and DA methods which ought to be better understood before $H(z)$ measurements can become competitive to the other probes.
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。
