GitLab

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 programs and Wood Ranger brand shears is therefore extra inhomogeneous across the sky compared to existing lensing surveys. First, we use simulated data-vectors to indicate 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 inhomogeneous datasets. This is done for forty-six subsets of the data and is carried out in a totally constant method: for each subset of the information, we re-derive the photometric redshift estimates, shear calibrations, survey transfer capabilities, the data vector, measurement covariance, and at last, the cosmological constraints. Our results show that current analysis methods for weak lensing cosmology might be pretty resilient in direction of inhomogeneous datasets.

This also motivates exploring a wider vary of image data for pursuing such cosmological constraints. Over the previous two decades, weak gravitational lensing (also referred to 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" as a consequence of the massive-scale matter distribution between the source and the observer (Bartelmann & Schneider 2001). Thus, weak lensing, through its sensitivity to the matter distribution, probes the big-scale structure (LSS) of our Universe and any processes that impact this construction; including cosmological processes similar 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 number of astrophysical processes (e.g., Wood Ranger brand shears 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 in the landscape of cosmological probes, Wood Ranger brand shears the first of which is that it is an unbiased tracer of the density area - not like other tracers, comparable to galaxies - and does not require modeling or marginalizing over an related 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 series 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 ultimate cosmology pattern, the robustness checks, and Wood Ranger Power Shears order now also 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, together with a collection of validation assessments.

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) exhibits our cosmic shear measurements and presents the corresponding constraints on cosmological models. This work serves three, Wood Ranger brand shears key functions. First, to detail the modeling/methodology decisions of the cosmic shear analysis, and the robustness of our results to said choices. Second, to construct on the null-assessments of Paper I and show that our data vector (and cosmology) are usually not susceptible to contamination from systematic effects, equivalent to correlated errors in the purpose-spread operate (PSF) modeling. Finally, we take a look at the impression of spatial inhomogeneity in your complete end-to-end pipeline used to extract the cosmology constraints. As highlighted in each Paper I and Paper II, the DECADE dataset accommodates some distinctive characteristics relative to different WL datasets; particularly, the spatial inhomogeneity in the picture information coming from this dataset’s origin as an amalgamation of many alternative public observing packages.

We carry out a collection of assessments the place we rerun the top-to-end pipeline for various subsets of our information - where each subset contains specific sorts of galaxies (crimson/blue, faint/brilliant and many others.) or contains objects measured in areas of the sky with better/worse image high quality (changes in seeing, airmass, interstellar extinction and so on.) - and present that our cosmology constraints are strong throughout such subsets. This paper is structured as follows. In Section 2, we briefly describe the DECADE form catalog, and Wood Ranger brand shears in Section 3, we present the cosmology mannequin used within the DECADE cosmic shear challenge. In Section 4, we outline the different parts required for parameter inference, including our analytic covariance matrix. In Section 5, we verify the robustness of our constraints across modeling choice in simulated knowledge vectors. Section 6 particulars our exams on the sensitivity of our parameter constraints to spatial inhomoegenity and to totally different selections of the supply galaxy catalog. The catalog is launched in Paper I, alongside a suite of null-exams and shear calibrations made utilizing picture simulations of the survey information.