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arXiv · 2610.23828

Revisiting the Mass and Scale Dependence of the "Lensing is Low" Effect with DECADE

Kimiko Queen·Abigail V. Fisher·Johannes U. Lange
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Abstract

Galaxy-galaxy lensing (GGL) is a critical probe of cosmology and galaxy formation. However, predicted GGL amplitudes tend to be $\sim 20-40\%$ higher than observations, primarily on small scales, a tension called the lensing-is-low problem. If not resolved through astrophysics or measurement systematics, this discrepancy may indicate a tension in our cosmological standard model. J. U. Lange et al. (2021), using foreground galaxies from the Baryon Oscillation Spectroscopic Survey (BOSS) and lensing measurements from the Sloan Digital Sky Survey (SDSS), presented evidence that this mismatch extends to large scales where astrophysical explanations are disfavored. We revisit this claim using lensing data from the Dark Energy Camera All Data Everywhere (DECADE) project. Compared to SDSS, the new DECADE measurements reduce the large-scale tension while leaving measurements on small scales mostly unchanged. Ultimately, these new results favor a scale dependence in the lensing-is-low problem.

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Kimiko Queen, Abigail V. Fisher, Johannes U. Lange. 2026-10-16. Revisiting the Mass and Scale Dependence of the "Lensing is Low" Effect with DECADE. https://doi.org/10.3847/2515-5172%2Faeb379

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