The DECADE Cosmic Shear Project III: Validation Of Analysis Pipeline Utilizing Spatially Inhomogeneous Data

We current the pipeline for the cosmic shear analysis of the Dark Energy Camera All Data Everywhere (DECADE) weak lensing dataset: a catalog consisting of 107 million galaxies observed 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 throughout the sky compared to existing lensing surveys. First, we use simulated data-vectors to point out the sensitivity of our constraints to different evaluation selections in our inference pipeline, including sensitivity to residual systematics. Next we use simulations to validate our covariance modeling for best shears for summer gardening inhomogeneous datasets. This is done for forty-six subsets of the info 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 switch capabilities, the information vector, measurement covariance, and at last, the cosmological constraints. Our results show that current analysis methods for weak lensing cosmology could be pretty resilient towards inhomogeneous datasets.



This also motivates exploring a wider range of image data for pursuing such cosmological constraints. Over the previous two many years, weak gravitational lensing (additionally known as weak lensing or cosmic shear) has emerged as a leading 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 to the refined bending of mild from distant "source galaxies" because of the massive-scale matter distribution between the source and the observer (Bartelmann & Schneider 2001). Thus, weak lensing, by its sensitivity to the matter distribution, probes the big-scale structure (LSS) of our Universe and any processes that impression this structure; including cosmological processes akin to modified gravity (e.g., Schmidt 2008) and primordial signatures (e.g., Anbajagane et al. 2024c; Goldstein et al. 2024), Wood Ranger Power Shears USA Wood Ranger Power Shears manual Power Shears shop as well as a wide variety 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 benefits in the landscape of cosmological probes, the primary of which is that it is an unbiased tracer of the density area - in contrast to other tracers, resembling galaxies - and does not require modeling or marginalizing over an associated bias parameter (Bartelmann & Schneider 2001). For these reasons, it is without doubt one of the leading probes of cosmology and has delivered some of our best shears for summer gardening constraints on cosmological parameters. This paper is part of a series of works detailing the DECADE cosmic shear evaluation. Anbajagane & Chang et al. 2025a (hereafter Paper I) describes the shape measurement method, the derivation of the final cosmology pattern, Wood Ranger Power Shears order now Wood Ranger Power Shears website Power Shears the robustness exams, and in addition the image 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 series of validation exams.



This work (Paper III) describes the methodology and validation of the model, in addition to a collection of survey inhomogeneity checks. Finally Anbajagane & Chang et al. 2025c (hereafter Paper IV) shows our cosmic shear measurements and presents the corresponding constraints on cosmological fashions. This work serves three, key functions. First, to element the modeling/methodology selections of the cosmic shear evaluation, and the robustness of our results to stated decisions. Second, to construct on the null-tests of Paper I and present that our knowledge vector (and cosmology) should not prone to contamination from systematic effects, equivalent to correlated errors in the point-spread function (PSF) modeling. Finally, we take a look at the impact of spatial inhomogeneity in the entire end-to-finish pipeline used to extract the cosmology constraints. As highlighted in each Paper I and Paper II, the DECADE dataset incorporates some distinctive traits relative to other WL datasets; notably, the spatial inhomogeneity within the picture data coming from this dataset’s origin as an amalgamation of many alternative public observing programs.



We carry out a collection of exams the place we rerun the top-to-finish pipeline for different subsets of our data - where every subset comprises particular kinds of galaxies (crimson/blue, faint/vibrant and so forth.) or incorporates objects measured in regions of the sky with higher/worse picture high quality (modifications in seeing, airmass, interstellar extinction etc.) - and present 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 present the cosmology model used in the DECADE cosmic shear project. In Section 4, we define the completely different parts required for parameter inference, together with our analytic covariance matrix. In Section 5, we test the robustness of our constraints across modeling alternative in simulated knowledge vectors. Section 6 details our checks on the sensitivity of our parameter constraints to spatial inhomoegenity and to completely different selections of the supply galaxy catalog. The catalog is launched in Paper I, alongside a collection of null-assessments and shear calibrations made utilizing picture simulations of the survey data.