近日，新西兰坎特伯雷大学Marco Galoppo团队报道了在十亿秒差距尺度上探测各向异性宇宙结构。相关论文于2026年6月24日发表在《自然》杂志上。

星系红移巡天绘制了宇宙网，并为宇宙学原理（支撑标准宇宙学模型的基础）所假设的——在足够大的尺度上宇宙是否变得统计均匀且各向同性——提供了关键观测检验。在这一框架下，在结构形成的非线性区之外，非均匀和各向异性的特征预计会迅速消退，反映了近各向同性的原初密度场及其后续引力演化。尽管这一观点得到了宇宙微波背景辐射各向异性小振幅²的支持，但星系分布中大尺度结构和空洞的复杂网络，以及报告可能存在偏离统计均匀性和各向同性的大尺度信号的独立探针，正日益对其提出挑战。

研究组表明星系分布呈现出持续的各向异性结构，延伸至约千兆秒差距尺度。利用成对距离的角度分布（ADPD）——一种无参数统计量，用于测量方向相关性——研究组检测到的各向异性信号超过了各向同性控制和几何匹配的ΛCDM模拟星表中的信号，保守显著性大于3σ。这些结果提供了直接证据，表明方向相干性持续至比标准框架预测更大的尺度，挑战了大尺度各向同性的假设。这要求重新评估均匀性和各向同性在观测宇宙中如何实现，并推动基于方向统计的宇宙学模型的新检验。

附：英文原文

Title: Detection of anisotropic cosmic structures on a gigaparsec scale

Author: Sylos Labini, Francesco, Galoppo, Marco

Issue&Volume: 2026-06-24

Abstract: Galaxy redshift surveys map the cosmic web and provide a key observational test of whether the Universe becomes statistically homogeneous and isotropic on sufficiently large scales, as assumed by the cosmological principle underpinning the standard cosmological model1. In this framework, beyond the nonlinear regime of structure formation, inhomogeneous and anisotropic features are expected to fade rapidly, reflecting the near-isotropic primordial density field and its subsequent gravitational evolution. Although supported by the small amplitude of cosmic microwave background anisotropies2, this view is increasingly challenged by the complex network of large-scale structures and voids in the galaxy distribution3,4,5,6, as well as by independent probes reporting possible large-scale deviations from statistical homogeneity7 and isotropy8,9. Here we show that the galaxy distribution exhibits persistent anisotropic structures extending to scales on the order of one gigaparsec. Using the Angular Distribution of Pairwise Distances (ADPD)10, a parameter-free statistic that measures directional correlations, we detect anisotropy signals exceeding those in isotropic controls and geometry-matched ΛCDM mock catalogues with conservative significance greater than 3σ. These results provide direct evidence that directional coherence persists to larger scales than predicted in the standard framework, challenging the assumption of large-scale isotropy. They call for a reassessment of how homogeneity and isotropy are realized in the observed Universe and motivate new tests of cosmological models based on directional statistics.

DOI: 10.1038/s41586-026-10702-5

Source: https://www.nature.com/articles/s41586-026-10702-5

期刊信息

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504

官方网址：http://www.nature.com/

投稿链接：http://www.nature.com/authors/submit_manuscript.html