Migkas Konstantinos
Leiden Observatory, Leiden University, PO Box 9513, Leiden 2300 RA, The Netherlands.
SRON Netherlands Institute for Space Research, Niels Bohrweg 4, Leiden 2333 CA, The Netherlands.
Philos Trans A Math Phys Eng Sci. 2025 Feb 13;383(2290):20240030. doi: 10.1098/rsta.2024.0030.
Scaling relations of galaxy clusters are a powerful probe of cosmic isotropy in the late Universe. Owing to their strong cosmological dependence, galaxy cluster scaling relations can obtain tight constraints on the spatial variation of cosmological parameters, such as the Hubble constant ([Formula: see text]), and detect large-scale bulk flow motions. Such tests are crucial to scrutinise the validity of [Formula: see text]CDM in the local Universe and determine at what cosmic scales (if any) extra-galactic objects converge to isotropy within the cosmic microwave background rest frame. This review describes the methodology for conducting cosmic isotropy tests with cluster scaling relations and examines possible systematic biases. We also discuss the results of past studies that reported statistically significant observed anisotropies in the local Universe. Finally, we explore the future potential of cluster scaling relations as a cosmic isotropy probe given the large amount of multi-wavelength cluster data expected in the near future.This article is part of the discussion meeting issue 'Challenging the standard cosmological model'.
星系团的标度关系是探测宇宙晚期宇宙各向同性的有力工具。由于星系团标度关系对宇宙学有很强的依赖性，它们可以对宇宙学参数的空间变化（如哈勃常数（[公式：见正文]））施加严格限制，并探测大规模的整体流动运动。此类检验对于仔细审查本地宇宙中[公式：见正文]冷暗物质模型的有效性以及确定在何种宇宙尺度（如果存在的话）上河外天体在宇宙微波背景静止参考系内趋于各向同性至关重要。本综述描述了利用团标度关系进行宇宙各向同性检验的方法，并研究了可能存在的系统偏差。我们还讨论了过去研究的结果，这些研究报告了在本地宇宙中观测到的具有统计显著性的各向异性。最后，鉴于在不久的将来预计会有大量多波长星系团数据，我们探讨了团标度关系作为宇宙各向同性探测器的未来潜力。本文是“挑战标准宇宙学模型”讨论会议题的一部分。
