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arXiv 2604.04436astro-ph.COastro-ph.GA
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利用Pantheon+和BAO对宇宙距离双关系的各向异性检验

Directional Tests of the Cosmic Distance Duality Relation using Pantheon+ and BAO

Vellore Institute of Technology（维洛尔理工学院）

Pushty Shrimankar, Gopal Kashyap

备注：
19 pages, 6 figures
发表信息：
JCAP10(2026)028
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AI总结：

本文利用Pantheon+和BAO数据，通过高斯过程重建角直径距离，检验宇宙距离双关系的各向异性，发现观测到的各向异性幅度与各向同性预期一致，得出95%置信度上限为0.025，无内在各向异性证据。

摘要：

我们利用Pantheon+Ia型超新星样本和红外观测（BAO）数据，对宇宙距离双关系（CDDR）的各向异性进行了模型无关的检验。通过高斯过程重建角直径距离，能够估计η(z)=D_L/[D_A(1+z)^2]而无需假设背景宇宙学模型。我们还允许可能的各向同性演化，参数化为η(z)=1+η_1 z，并发现红移依赖的偏差，其显著性取决于假设的超新星校准。各向异性通过双极调制建模，并利用基于完整协方差的似然约束。为评估统计显著性，我们构建了保持红移分布和调查选择函数的零假设实现。我们发现观测到的双极幅度与各向同性预期一致，并低于统计波动和调查几何诱导的水平。我们得出稳健的95%上限A_95=0.025，稳定于不同超新星校准选择。我们未发现CDDR中的内在各向异性。我们的结果强调了在各向异性搜索中考虑调查选择效应的重要性，并提供了一个可行的框架来测试宇宙学关系中的方向偏差。

英文摘要：

We present a model-independent test of anisotropy in the cosmic distance duality relation (CDDR), $D_L=(1+z)^2 D_A$, using the Pantheon+ type Ia supernova sample and baryon acoustic oscillation (BAO) data. The angular diameter distance is reconstructed via Gaussian Processes, enabling an estimate of $η(z)=D_L/[D_A(1+z)^2]$ without assuming a background cosmology. We also allow for a possible isotropic evolution, parameterized as $η(z)=1+η_1 z$, and find a redshift-dependent deviation whose significance depends on the assumed supernova calibration. Anisotropy is modeled through a dipole modulation and constrained using a full covariance-based likelihood. To assess statistical significance, we construct null realizations that preserve both the redshift distribution and the survey selection function. We find that the observed dipole amplitude is consistent with isotropic expectations and lies below the levels induced by statistical fluctuations and survey geometry. We obtain a robust 95\% upper bound $A_{95}=0.025$, stable across different supernova calibration choices. We find no evidence for intrinsic anisotropy in the CDDR. Our results highlight the importance of accounting for survey selection effects in anisotropy searches and provide a viable framework for testing directional deviations in cosmological relations.

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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