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arXiv 2001.04645astro-ph.CO
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非平坦$ΛCDM$模型的观测约束和使用跃迁红移的零检验

Observational constraints on the non-flat $ΛCDM$ model and a null test using the transition redshift

Velasquez-Toribio, A. M, Magnago, A. dos R

摘要:

标准宇宙学模型的一个自然延伸是包含曲率作为自由参数的模型。在这项工作中,我们详细研究的观测约束的非平坦$ΛCDM$模型使用两个主要的几何测试:SNIa和哈勃参数测量。在一般情况下,我们表明,观测约束的参数的$ΛCDM$模型强烈依赖于曲率参数。特别地,我们研究了由物质支配的宇宙的跃迁红移($z_{t}$)的约束条件下的宇宙学常数占主导地位的宇宙。使用这个可观察的,我们构造了一个新的零测试定义$ζ= z_{t, flat}-z_{t, non flat}$。该检验仅依赖于哈勃参数、哈勃常数和物质密度参数的数据。然而,它并不像文献中的许多测试那样依赖于可观察量的导数。为了重建这个测试,我们使用高斯过程方法。当我们使用$PLANCK/2018$的最佳拟合参数值时,我们没有发现数据和标准模型(平面$ΛCDM$)之间存在不一致的证据,但如果我们使用来自$RIESS/2018$的$H_{0}$值,我们发现在标准模型中存在不一致。然而,重要的是要注意,哈勃参数数据对于可靠的统计分析有很大的误差。

英文摘要:

A natural extension of the standard cosmological model are models that include curvature as a free parameter. In this work we study in detail the observational constraints on the non-flat $ΛCDM$ model using the two main geometric tests: SNIa and Hubble parameter measurements. In general we show that the observational constraints on the parameters of the $ΛCDM$ model strongly depend on the curvature parameter. In particular, we study the constraints on the transition redshift ($z_{t}$) of a universe dominated by matter for a universe dominated by the cosmological constant. Using this observable we construct a new null test defining $ζ= z_{t, flat}-z_{t, non flat}$. This test depends only on the data of the Hubble parameter, the Hubble constant and the matter density parameter. However, it does not depend on derivative of an observable as generally many tests in the literature. To reconstruct this test, we use the Gaussian process method. When we use the best-fit parameters values of $PLANCK/2018$, we find no evidence of a disagreement between the data and the standard model (flat $ΛCDM$), but if we use the value $H_{0}$ from $RIESS/2018$ we found a disagreement with respect at the standard model. However, it is important to note that the Hubble parameter data has large errors for a solid statistical analysis.

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。

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