Confirming the uniformity of the Hubble flow with Pantheon+ Supernovae

Abstract

According to the perturbed Friedmann model, the difference between Hubble constant measurements in two rest frames, at leading order in velocity, is determined solely by the relative motion of the observers and remains unaffected by the peculiar velocities of the sources. This implies that, when averaging over a sufficiently large and distant set of sources where local nonlinear inhomogeneities are diminished, such a difference should vanish, so that the Hubble flow is statistically uniform, as predicted by the Cosmological Principle -- a core assumption of the standard cosmological paradigm. In previous works, distance measurement compilations, e.g. the CosmicFlows-3 catalogue, were used for this purpose, as it comprises a large number ($\sim 10^4$) of sources of different types. Due to the increasing amount of precise luminosity distance measurements of Type Ia Supenovae (SNe) in the last few years, in this work we investigate whether we can confirm the uniformity of the Hubble flow with low-$z$ SN distances only. By means of the Pantheon+ and SH0ES compilation, we find that the results align well with previous works based on the CF3 catalogue, and are in good agreement with the expected Hubble variance in the standard model across cosmic scales of $20-150$ Mpc. Notably, the Hubble constant difference $\Delta H_0\approx 0$ is observed at around $85$ Mpc. Despite the smaller sample size ($\sim 10^2$ versus $\sim 10^4$) relative to CF3 at those scales, our analysis show that the Pantheon+ and SH0ES dataset supports the standard model paradigm, which indicates that the Hubble flow becomes statistically uniform at around $70-100$ Mpc, which is compatible with independent determinations of the homogeneity scale based on galaxy number counts.

11 pages, 9 figures

References in corpus (24)

• A Comprehensive Measurement of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncertainty from the Hubble Space Telescope and the SH0ES Team
• 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
• The Pantheon+ Analysis: Cosmological Constraints
• Dark Energy Survey Year 3 Results: Cosmological Constraints from Galaxy Clustering and Weak Lensing
• DESI 2024 VI: Cosmological Constraints from the Measurements of Baryon Acoustic Oscillations
• The Pantheon+ Analysis: The Full Dataset and Light-Curve Release
• The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters
• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Is the Observable Universe Consistent with the Cosmological Principle?
• Interpreting DESI's evidence for evolving dark energy
• The Pantheon+ Analysis: Improving the Redshifts and Peculiar Velocities of Type Ia Supernovae Used in Cosmological Analyses
• Analyzing the Large-Scale Bulk Flow using CosmicFlows4: Increasing Tension with the Standard Cosmological Model
• Hints of FLRW Breakdown from Supernovae
• The Pantheon+ Analysis: Evaluating Peculiar Velocity Corrections in Cosmological Analyses with Nearby Type Ia Supernovae
• Homogeneity and isotropy in the 2MASS Photometric Redshift catalogue
• Model-independent cosmological inference post DESI DR1 BAO measurements
• Evaluating bulk flow estimators for CosmicFlows-4 measurements
• The kinematic dipole in galaxy redshift surveys
• Cosmic homogeneity: a spectroscopic and model-independent measurement
• Measuring the cosmic homogeneity scale with SDSS-IV DR16 Quasars
• Frames of most uniform Hubble flow
• No evidence for local $H_0$ anisotropy from Tully--Fisher or supernova distances
• Can the angular scale of cosmic homogeneity be used as a cosmological test?