A null test of the Cosmological Principle with BAO measurements

Abstract

The assumption of a Friedmann-Lemaître-Roberton-Walker (FLRW) Universe is one of the fundamental pillars of modern Cosmology. It is crucial to confront it against cosmological observations in order to confirm (or rule out) the validity of the $\Lambda$CDM paradigm. We perform a consistency test of the FLRW metric using measurements of both radial and transversal modes of Baryonic Acoustic Oscillations in a model-independent fashion using Gaussian Processes. The impact of different prior assumptions for the sound horizon scale and the Hubble Constant is also explored. We find a mild deviation of the FLRW hypothesis ($\gtrsim 3\sigma$ confidence level) at lower redshift ranges ($0.1<z<0.3$) under the assumption the SH0ES $H_0$ prior, which does not occur for the $H_0$ prior by Planck. We also find that different reconstruction kernels reduce the statistical significance of such a deviation. At higher reshift ranges, the null test are able to confirm the FLRW assumption within $3\sigma$ confidence level regardless of the priors.

13 pages, 4 figures. Revised manuscript with extended analysis, citations included, and fixed typos. Accepted for publication in Phys. Dark. Univ. Code provided at https://github.com/astrobengaly/null_test_FLRW

References in corpus (26)

• In the Realm of the Hubble tension $-$ a Review of Solutions
• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological Implications from two Decades of Spectroscopic Surveys at the Apache Point observatory
• Dark Energy Survey Year 3 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
• Two new diagnostics of dark energy
• Gaussian Process Cosmography
• A Test of the Cosmological Principle with Quasars
• To H0 or not to H0?
• A general test of the Copernican Principle
• Probing cosmic isotropy with a new X-ray galaxy cluster sample through the $L_{\text{X}}-T$ scaling relation
• Does Hubble Tension Signal a Breakdown in FLRW Cosmology?
• A litmus test for Lambda
• Chameleon dark energy can resolve the Hubble tension
• BAO angular scale at z_eff = 0.11 with the SDSS blue galaxies
• Constraining Teleparallel Gravity through Gaussian Processes
• Novel null tests for the spatial curvature and homogeneity of the Universe and their machine learning reconstructions
• Non-parametric reconstruction of the cosmological \textit{jerk} parameter
• Towards a model-independent reconstruction approach for late-time Hubble data
• A data-driven Reconstruction of Horndeski gravity via the Gaussian processes
• Machine Learning improved fits of the sound horizon at the baryon drag epoch
• A model-independent reconstruction of dark sector interactions
• Peculiar motion of Solar system from the Hubble diagram of supernovae Ia and its implications for cosmology
• Multi-tasking the growth of cosmological structures
• Galaxy correlations and the BAO in a void universe: structure formation as a test of the Copernican Principle
• Measuring the Homogeneity of the Universe Using Polarization Drift
• Complementary consistency test of the Copernican principle via Noether's theorem and machine learning forecasts
• Solar system peculiar motion from the Hubble diagram of quasars and testing the Cosmological Principle

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