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arXiv 2008.12628astro-ph.CO
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用Alcock-Paczynski效应估算SDSS-IV类星体目录中的宇宙加速

Assessing Cosmic Acceleration with the Alcock-Paczynski Effect in the SDSS-IV Quasar Catalog

Fulvio Melia, Jin Qin, Tong-Jie Zhang

摘要:

宇宙的几何形状可以用阿尔科克-帕钦斯基(AP)效应来探测,其中观测到的源的球形分布相对于其角尺寸的红移大小根据假设的宇宙学模型而变化。然而,由于缺乏合适的源和减轻的天体物理因素,如内部红移空间扭曲和鲜为人知的源演化,这种效应在过去的应用受到限制。在这封信中,我们介绍了一种基于AP效应的新测试,该测试避免使用空间约束系统,而是依赖于斯隆数字巡天IV中红移z < 1.5的类星体子样本,当该目录通过即将进行的巡天扩展时,可能会扩展到更高的红移和更高的精度。本文用这种方法研究了三种相关的Friedmann-Lemaitre-Robertson-Walker(FLRW)宇宙学中的红移依赖膨胀率:LCDM宇宙学,它预言了在z ~ 0.7处从减速到加速的转变; Einstein-de Sitter宇宙学,它总是减速的;以及R_h=ct宇宙学,它以恒定速率膨胀。LCDM与这些数据是一致的,但R_h=ct总体上是有利的。

英文摘要:

The geometry of the Universe may be probed using the Alcock-Paczynski (AP) effect, in which the observed redshift size of a spherical distribution of sources relative to its angular size varies according to the assumed cosmological model. Past applications of this effect have been limited, however, by a paucity of suitable sources and mitigating astrophysical factors, such as internal redshift-space distortions and poorly known source evolution. In this Letter, we introduce a new test based on the AP effect that avoids the use of spatially bound systems, relying instead on sub-samples of quasars at redshifts z < 1.5 in the Sloan Digital Sky Survey IV, with a possible extension to higher redshifts and improved precision when this catalog is expanded by upcoming surveys. We here use this method to probe the redshift-dependent expansion rate in three pertinent Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmologies: LCDM, which predicts a transition from deceleration to acceleration at z ~ 0.7; Einstein-de Sitter, in which the Universe is always decelerating; and the R_h=ct universe, which expands at a constant rate. LCDM is consistent with these data, but R_h=ct is favoured overall.

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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