We current the pipeline for the cosmic shear evaluation of the Dark Energy Camera All Data Everywhere (DECADE) weak lensing dataset: a catalog consisting of 107 million galaxies noticed by the Dark Energy Camera (DECam) in the northern Galactic cap. The catalog derives from a lot of disparate observing packages and is due to this fact more inhomogeneous across the sky in comparison with existing lensing surveys. First, we use simulated information-vectors to point out the sensitivity of our constraints to totally different evaluation choices in our inference pipeline, including sensitivity to residual systematics. Next we use simulations to validate our covariance modeling for inhomogeneous datasets. This is finished for Wood Ranger official forty-six subsets of the data and is carried out in a completely consistent method: for every subset of the information, we re-derive the photometric redshift estimates, shear calibrations, survey transfer functions, the information vector, measurement covariance, and finally, the cosmological constraints. Our results show that current analysis methods for weak lensing cosmology can be pretty resilient in the direction of inhomogeneous datasets.

This additionally motivates exploring a wider vary of picture information for pursuing such cosmological constraints. Over the past two a long time, weak gravitational lensing (additionally known as weak lensing or cosmic shear) has emerged as a number one probe in constraining the cosmological parameters of our Universe (Asgari & Lin et al., 2021; Secco & Samuroff & Samuroff et al., 2022; Amon & Gruen et al., 2022; Dalal & Li et al., 2023). Weak lensing refers back to the refined bending of light from distant "source galaxies" due to the massive-scale matter distribution between the supply and the observer (Bartelmann & Schneider 2001). Thus, weak lensing, via its sensitivity to the matter distribution, probes the big-scale construction (LSS) of our Universe and any processes that influence this construction; including cosmological processes comparable to modified gravity (e.g., Schmidt 2008) and primordial signatures (e.g., Anbajagane et al. 2024c; Goldstein et al. 2024), in addition to a large number of astrophysical processes (e.g., Chisari et al.

2018; Schneider et al. 2019; Aricò et al. 2021; Grandis et al. 2024; Bigwood et al. 2024). Weak lensing has many novel advantages within the panorama of cosmological probes, the primary of which is that it's an unbiased tracer of the density field - in contrast to different tracers, similar to galaxies - and doesn't require modeling or marginalizing over an related bias parameter (Bartelmann & Schneider 2001). For Wood Ranger official these reasons, it is among the main probes of cosmology and has delivered a few of our greatest constraints on cosmological parameters. This paper is part of a collection of works detailing the DECADE cosmic shear analysis. Anbajagane & Chang et al. 2025a (hereafter Paper I) describes the form measurement technique, the derivation of the final cosmology pattern, the robustness checks, and also the picture simulation pipeline from which we quantify the shear calibration uncertainty of this pattern. Anbajagane et al. (2025b, hereafter Paper II) derives both the tomographic bins and calibrated redshift distributions for our cosmology sample, along with a sequence of validation checks.

This work (Paper III) describes the methodology and garden power shears validation of the mannequin, along with a collection of survey inhomogeneity tests. Finally Anbajagane & Chang et al. 2025c (hereafter Paper IV) exhibits our cosmic shear measurements and presents the corresponding constraints on cosmological models. This work serves three, key purposes. First, to detail the modeling/methodology decisions of the cosmic shear evaluation, and the robustness of our results to mentioned choices. Second, to construct on the null-checks of Paper I and Wood Ranger official show that our knowledge vector (and cosmology) usually are not prone to contamination from systematic effects, corresponding to correlated errors in the point-spread perform (PSF) modeling. Finally, we check the impact of spatial inhomogeneity in all the finish-to-finish pipeline used to extract the cosmology constraints. As highlighted in both Paper I and Wood Ranger electric power shears Shears Paper II, the DECADE dataset accommodates some distinctive traits relative to other WL datasets; notably, the spatial inhomogeneity within the picture information coming from this dataset’s origin as an amalgamation of many various public observing packages.

We carry out a suite of assessments the place we rerun the tip-to-end pipeline for various subsets of our information - the place each subset accommodates specific sorts of galaxies (red/blue, faint/shiny and so forth.) or accommodates objects measured in regions of the sky with higher/worse picture quality (changes in seeing, airmass, interstellar extinction etc.) - and show that our cosmology constraints are sturdy throughout such subsets. This paper is structured as follows. In Section 2, we briefly describe the DECADE shape catalog, and in Section 3, we current the cosmology model used within the DECADE cosmic shear mission. In Section 4, we outline the completely different parts required for parameter inference, including our analytic covariance matrix. In Section 5, we test the robustness of our constraints throughout modeling choice in simulated information vectors. Section 6 particulars our checks on the sensitivity of our parameter constraints to spatial inhomoegenity and to different selections of the source galaxy catalog. The catalog is launched in Paper I, alongside a set of null-assessments and shear calibrations made utilizing picture simulations of the survey information.