Late-time distance consistency and model-independent curvature inference with strong lensing, quasars, and galaxy clusters
Abstract
We revisit a late-time, model-independent distance-consistency framework that combines strong gravitational lensing systems (SGLS), ultraviolet/X-ray quasars (QSOs), and 38 Sunyaev--Zel'dovich/X-ray galaxy-cluster angular-diameter distances. The analysis focuses on systematics rather than on presenting a competitive curvature measurement. Starting from the 158-system SGLS catalog, we exclude 30 systems that violate the lensing-geometric requirement DA,ls/DA,s<1 in the isothermal reference case γlens=2, leaving a fixed 128-system SGLS parent sample for cross-matching with 1598 QSOs. A deterministic maximum-cardinality, minimum-mismatch one-to-one assignment yields 100 SGLS--QSO pairs at the nominal Δd/d=5% threshold. We propagate the measured X-ray flux uncertainties and the intrinsic QSO scatter, and, crucially, we include the full 38×38 covariance induced by using the same QSO distances in the kernel-smoothed cluster predictions. With ΩK∼𝒰[−10,10], the joint posterior is ΩK=2.085+1.634−1.103 (68\%; central 95\% interval $[0.269,6.028]$). We do not interpret the positive shift as evidence for an open Universe. \added{This positive posterior offset is driven by cross-probe calibration tensions, sample-assignment effects, and the cluster anchor; it cannot be attributed to the intrinsic spatial geometry of the Universe.} The SGLS+QSO data alone leave curvature essentially prior dominated, ΩK=0.70+6.33−7.12, whereas removing only the off-diagonal cluster covariance moves the posterior to ΩK=5.21+2.46−2.07. Thus the cluster anchor supplies most of the curvature constraining power and its covariance materially changes the posterior location.
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BibTeX
@misc{hu2026latetime,
title = {{Late-time distance consistency and model-independent curvature inference with strong lensing, quasars, and galaxy clusters}},
author = {Jian Hu and Yi Liu and Jian Ping Hu and Zhongmu Li},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.26097},
eprint = {2610.26097},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.26097},
}
RIS
TY - UNPB
TI - Late-time distance consistency and model-independent curvature inference with strong lensing, quasars, and galaxy clusters
AU - Jian Hu
AU - Yi Liu
AU - Jian Ping Hu
AU - Zhongmu Li
PY - 2026
DA - 2026/10/19
PB - arXiv
DO - 10.48550/arxiv.2610.26097
UR - https://arxiv.org/abs/2610.26097
AB - We revisit a late-time, model-independent distance-consistency framework that combines strong gravitational lensing systems (SGLS), ultraviolet/X-ray quasars (QSOs), and 38 Sunyaev--Zel'dovich/X-ray galaxy-cluster angular-diameter distances. The analysis focuses on systematics rather than on presenting a competitive curvature measurement. Starting from the 158-system SGLS catalog, we exclude 30 systems that violate the lensing-geometric requirement D_A,ls/D_A,s<1 in the isothermal reference case γ_lens=2, leaving a fixed 128-system SGLS parent sample for cross-matching with 1598 QSOs. A deterministic maximum-cardinality, minimum-mismatch one-to-one assignment yields 100 SGLS--QSO pairs at the nominal Δd/d=5% threshold. We propagate the measured X-ray flux uncertainties and the intrinsic QSO scatter, and, crucially, we include the full 38×38 covariance induced by using the same QSO distances in the kernel-smoothed cluster predictions. With Ω_K∼𝒰[−10,10], the joint posterior is Ω_K=2.085^+1.634_−1.103 (68\%; central 95\% interval $[0.269,6.028]$). We do not interpret the positive shift as evidence for an open Universe. \added{This positive posterior offset is driven by cross-probe calibration tensions, sample-assignment effects, and the cluster anchor; it cannot be attributed to the intrinsic spatial geometry of the Universe.} The SGLS+QSO data alone leave curvature essentially prior dominated, Ω_K=0.70^+6.33_−7.12, whereas removing only the off-diagonal cluster covariance moves the posterior to Ω_K=5.21^+2.46_−2.07. Thus the cluster anchor supplies most of the curvature constraining power and its covariance materially changes the posterior location.
ER -