2025/10/02 by Paula S. Ferreira, Ulisses Ribeiro, Ferreira, Paula S. +6 · 1 citation
Engineering · Medicine · Physics and Astronomy · #Advanced MRI Techniques and Applications #Advanced X-ray and CT Imaging #Atomic and Subatomic Physics Research #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences
paper · pdf · doi:10.48550/arxiv.2510.02144
openalex publication_date 2025/10/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We employ a model-independent approach in both the correlation function estimation and the angular BAO feature estimation by computing the angular two-point correlation function. First, we conducted a series of tests to the available DESI tracers to check their representativeness to angular clustering; the result was that, considering the completeness of the first data release across the footprint, we could only make use of the BGS sample for the effective redshifts 0.21 (BGS1) and 0.25 (BGS2). For a reliable analysis in such low redshift, we consider Lagrangian Perturbation Theory at first order on our mocks, which approximately reproduces the expected non-linearities, and generate the corresponding random catalogues. We use a purely statistical method to correct the projection effects and find that our results show reasonable agreement with the θ\rm BAO expected by the CPL parameters obtained by DESI DR1, being BGS1 11.78 ± 1.12 degrees and BGS2 11.81 ± 1.20 degrees. This means a tension at the 1.5σ (2.6σ) level for BGS1 (BGS2) CPL parametrization, while a 2σ (3.3σ) discrepancy within the predicted by ΛCDM. We conclude that, with the current sample available, the use of an angular correlation function serving as the BAO probe, although prefers the CPL parametrization, does not provide conclusive results regarding the best cosmological model.