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

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Revision as of 10:29, 16 September 2025 by AraPatnode0 (talk | contribs) (Created page with "<br>We present 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 noticed by the Dark Energy Camera (DECam) in the northern Galactic cap. The catalog derives from a large number of disparate observing applications and is therefore extra inhomogeneous across the sky compared to existing lensing surveys. First, we use simulated data-vectors to point out the sen...")
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We present 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 noticed by the Dark Energy Camera (DECam) in the northern Galactic cap. The catalog derives from a large number of disparate observing applications and is therefore extra inhomogeneous across the sky compared to existing lensing surveys. First, we use simulated data-vectors to point out the sensitivity of our constraints to totally different analysis choices in our inference pipeline, together with sensitivity to residual systematics. Next we use simulations to validate our covariance modeling for inhomogeneous datasets. This is completed for forty-six subsets of the info and is carried out in a fully constant method: for every subset of the info, we re-derive the photometric redshift estimates, shear calibrations, survey transfer capabilities, the data vector, measurement covariance, and finally, the cosmological constraints. Our outcomes present that existing evaluation strategies for weak lensing cosmology may be pretty resilient in the direction of inhomogeneous datasets.



This additionally motivates exploring a wider range of image information for pursuing such cosmological constraints. Over the previous two decades, 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 to the delicate bending of light from distant "source galaxies" due to the large-scale matter distribution between the supply and the observer (Bartelmann & Schneider 2001). Thus, weak lensing, by way of its sensitivity to the matter distribution, probes the large-scale structure (LSS) of our Universe and any processes that impression this structure; including cosmological processes comparable to modified gravity (e.g., Schmidt 2008) and primordial signatures (e.g., Anbajagane et al. 2024c; Goldstein et al. 2024), as well as a large 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 advantages within the landscape of cosmological probes, the primary of which is that it is an unbiased tracer of the density area - unlike different tracers, comparable to galaxies - and doesn't require modeling or marginalizing over an associated bias parameter (Bartelmann & Schneider 2001). For these reasons, it is one of the main probes of cosmology and has delivered some of our best constraints on cosmological parameters. This paper is a part of a collection of works detailing the DECADE cosmic shear analysis. Anbajagane & Chang et al. 2025a (hereafter Paper I) describes the shape measurement technique, the derivation of the final cosmology pattern, the robustness tests, and in addition the picture simulation pipeline from which we quantify the shear calibration uncertainty of this pattern. Anbajagane et al. (2025b, hereafter Paper II) derives each the tomographic bins and calibrated redshift distributions for our cosmology pattern, along with a collection of validation tests.



This work (Paper III) describes the methodology and validation of the model, along with a collection of survey inhomogeneity exams. Finally Anbajagane & Chang et al. 2025c (hereafter Paper IV) shows our cosmic shear measurements and presents the corresponding constraints on cosmological models. This work serves three, key purposes. First, to detail the modeling/methodology selections of the cosmic shear evaluation, and the robustness of our outcomes to mentioned decisions. Second, to construct on the null-assessments of Paper I and show that our data vector (and cosmology) usually are not inclined to contamination from systematic effects, reminiscent of correlated errors in the point-unfold operate (PSF) modeling. Finally, Wood Ranger Power Shears website we take a look at the affect of spatial inhomogeneity in your complete end-to-finish pipeline used to extract the cosmology constraints. As highlighted in both Paper I and Paper II, the DECADE dataset incorporates some unique traits relative to different WL datasets; significantly, the spatial inhomogeneity within the picture information coming from this dataset’s origin as an amalgamation of many various public observing applications.



We perform a set of checks the place we rerun the end-to-finish pipeline for various subsets of our knowledge - the place each subset incorporates specific kinds of galaxies (red/blue, Wood Ranger Power Shears website faint/brilliant etc.) or accommodates objects measured in regions of the sky with better/worse image quality (modifications in seeing, airmass, interstellar extinction etc.) - and show that our cosmology constraints are robust throughout such subsets. This paper is structured as follows. In Section 2, Wood Ranger Power Shears website we briefly describe the DECADE form catalog, Wood Ranger Power Shears specs Wood Ranger Power Shears shop Power Shears features and in Section 3, we present the cosmology mannequin used within the DECADE cosmic shear mission. In Section 4, we define the completely different components required for parameter inference, together with our analytic covariance matrix. In Section 5, we verify the robustness of our constraints across modeling selection in simulated information vectors. Section 6 details our assessments on the sensitivity of our parameter constraints to spatial inhomoegenity and to completely different selections of the supply galaxy catalog. The catalog is introduced in Paper I, alongside a suite of null-tests and shear calibrations made utilizing image simulations of the survey knowledge.