Finding the distribution of matter using lenses - II: deconvolution-based reconstruction with 3x2pt measurements
Abstract
We present a deconvolution-based framework for testing scale-dependent departures of the late-time matter power spectrum from a fiducial cosmological model using 3×2pt measurements. We introduce a free-form scale-dependent modulation A(k) of the fiducial nonlinear matter power spectrum and construct the linear response of binned galaxy-clustering, galaxy-galaxy-lensing, and cosmic-shear spectra to the discretized modulation A(k). The response is evaluated with full-sky, beyond-Limber kernels including density, redshift-space-distortion, gravitational-shear, and intrinsic-alignment contributions. We reconstruct A(k) using a regularized modified Richardson-Lucy algorithm, with weak diffusion in ln k and selection of the minimum-χ2 solution along the iteration history. Using Rubin/LSST Year 10-like synthetic data, we find that oscillatory modulations with amplitudes ≳1% can be recovered over 0.1≲ k≲0.5 Mpc−1, provided the oscillation frequency f≲10 on log10[k/(0.2 Mpc−1)]. We further introduce a posterior-weighted consistency statistic calibrated with posterior-predictive null mocks, thereby accounting for cosmological and nuisance-parameter uncertainties without relying on Wilks' theorem. The null case is consistent with A(k)=1, while a 1% oscillatory modulation is detected at ∼ 2.6σ. These results demonstrate the potential of regularized deconvolution as a model-independent consistency test of the matter power spectrum in future 3×2pt surveys.
Related
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BibTeX
@misc{jiang2026finding,
title = {{Finding the distribution of matter using lenses - II: deconvolution-based reconstruction with 3x2pt measurements}},
author = {Jun-Qian Jiang and Ajoy Dawn and Dhiraj Kumar Hazra and Benjamin L'Huillier and Arman Shafieloo},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.08460},
eprint = {2609.08460},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.08460},
}
RIS
TY - UNPB
TI - Finding the distribution of matter using lenses - II: deconvolution-based reconstruction with 3x2pt measurements
AU - Jun-Qian Jiang
AU - Ajoy Dawn
AU - Dhiraj Kumar Hazra
AU - Benjamin L'Huillier
AU - Arman Shafieloo
PY - 2026
DA - 2026/09/08
PB - arXiv
DO - 10.48550/arxiv.2609.08460
UR - https://arxiv.org/abs/2609.08460
AB - We present a deconvolution-based framework for testing scale-dependent departures of the late-time matter power spectrum from a fiducial cosmological model using 3×2pt measurements. We introduce a free-form scale-dependent modulation A(k) of the fiducial nonlinear matter power spectrum and construct the linear response of binned galaxy-clustering, galaxy-galaxy-lensing, and cosmic-shear spectra to the discretized modulation A(k). The response is evaluated with full-sky, beyond-Limber kernels including density, redshift-space-distortion, gravitational-shear, and intrinsic-alignment contributions. We reconstruct A(k) using a regularized modified Richardson-Lucy algorithm, with weak diffusion in ln k and selection of the minimum-χ^2 solution along the iteration history. Using Rubin/LSST Year 10-like synthetic data, we find that oscillatory modulations with amplitudes ≳1% can be recovered over 0.1≲ k≲0.5 Mpc^−1, provided the oscillation frequency f≲10 on log_10[k/(0.2 Mpc^−1)]. We further introduce a posterior-weighted consistency statistic calibrated with posterior-predictive null mocks, thereby accounting for cosmological and nuisance-parameter uncertainties without relying on Wilks' theorem. The null case is consistent with A(k)=1, while a 1% oscillatory modulation is detected at ∼ 2.6σ. These results demonstrate the potential of regularized deconvolution as a model-independent consistency test of the matter power spectrum in future 3×2pt surveys.
ER -