论文标题

全形星系功率光谱和曲率张力

Full-Shape Galaxy Power Spectra and the Curvature Tension

论文作者

Glanville, Aaron, Howlett, Cullan, Davis, Tamara M.

论文摘要

有了最近的证据表明,早期和晚期宇宙宇宙学探针中可能存在“曲率张力”,有效的大规模结构(EFTOFLSS)的现场理论已成为一个有希望的新框架,可以在$ω_k$上产生限制,这些框架与CMB测量值无关,并且可以进入其他大型结构分析。在这项工作中,我们使用EFTOFLSS同时限制了6DFG,BOSS和EBOSS目录的测量,这代表了迄今为止最广泛的曲率完整形状研究。在$ω_bh^2 $上拟合全形数据,并修复了$ n_s $,我们测量$ω__k= -0.089^{+0.049} _ { - 0.046} $,对应于$ \ sim2σ$ curvature。我们认为,这一结果不能通过拟合方法中的假设来偏向平坦。使用贝叶斯证据比率,我们的全形数据分配了2:1的投注赔率支持曲率,这表明目前的测量值与平坦和弯曲的宇宙学模型均广泛兼容。当我们的全形样品与Planck 2018 CMB测量结果结合使用时,我们打破了几何变性,并恢复了$ω_k$ of $ -0.0041^{+0.0026} _ { - 0.0021} $上的$ω_k$ of $ω_k$。使用可疑性统计量(建立在标准贝叶斯因素上),我们发现了普朗克2018与我们的全形测量套件之间存在适度张力的证据,其显着性为$ 1.76 ^{+0.14} _ { - 0.11}σ$($ p \ sim 0.08 \ pm 0.02 $)。这些结果表明,在持续的曲率张力辩论中,全形聚类测量值作为CMB独立的曲率探针的有用性。

With recent evidence for a possible "curvature tension" among early and late universe cosmological probes, Effective Field Theories of Large Scale Structure (EFTofLSS) have emerged as a promising new framework to generate constraints on $Ω_k$ that are independent of both CMB measurements, and some of the assumptions of flatness that enter into other large-scale structure analyses. In this work we use EFTofLSS to simultaneously constrain measurements from the 6dFGS, BOSS, and eBOSS catalogues, representing the most expansive full-shape investigation of curvature to date. Fitting the full-shape data with a BBN prior on $Ω_b h^2$ and fixed $n_s$, we measure $Ω_k = -0.089^{+0.049}_{-0.046}$, corresponding to a $\sim 2 σ$ preference for curvature. We argue that this result cannot be biased towards flatness by assumptions in the fitting methodology. Using the Bayesian evidence ratio our full-shape data assigns betting odds of 2:1 in favour of curvature, indicating present measurements remain broadly compatible with both flat and curved cosmological models. When our full-shape sample is combined with Planck 2018 CMB measurements, we break the geometric degeneracy and recover a joint fit on $Ω_k$ of $-0.0041^{+0.0026}_{-0.0021}$. Using the suspiciousness statistic (built on the standard Bayes factor), we find evidence for a moderate tension between Planck 2018 and our suite of full-shape measurements, at a significance of $1.76 ^{+0.14}_{-0.11} σ$ ($p \sim 0.08 \pm 0.02$). These results demonstrate the usefulness of full-shape clustering measurements as a CMB independent probe of curvature in the ongoing curvature tension debate.

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