Is there really a Hubble tension?

Abstract

The heliocentric redshifts ($z_{\mathrm{hel}}$) reported for 150 Type Ia supernovae in the Pantheon compilation are significantly discrepant from their corresponding values in the JLA compilation. Both catalogues include corrections to the redshifts and magnitudes of the supernovae to account for the motion of the heliocentric frame relative to the `CMB rest frame', as well as corrections for the directionally coherent bulk motion of local galaxies with respect to this frame. The latter is done employing modelling of peculiar velocities which assume the $\Lambda$CDM cosmological model but nevertheless provide evidence for residual bulk flows which are discordant with this model (implying that the observed Universe is in fact anisotropic). Until recently such peculiar velocity corrections in the Pantheon catalogue were made at redshifts exceeding 0.2 although there is no data on which to base such corrections. We study the impact of these vexed issues on the 4.4 $\sigma$ discrepancy between the Hubble constant of $H_0=67.4\pm 0.5$ km/s/Mpc inferred from observations of CMB anisotropies by Planck assuming $\Lambda$CDM, and the measurement of $H_0=73.5\pm 1.4$ km/s/Mpc by the SH0ES project which extended the local distance ladder using Type Ia supernovae. Using the same methodology as the latter study we find that for supernovae whose redshifts are discrepant between Pantheon and JLA with $\Delta z_{\mathrm{hel}}>0.0025$, the Pantheon redshifts favour $H_0\simeq 72$ km/s/Mpc, while the JLA redshifts favour $H_0\simeq 68$ km/s/Mpc. Thus the discrepancies between SNe Ia datasets are sufficient to undermine the claimed `Hubble tension'. We further note the systematic variation of $H_0$ by $\sim$ 6-9 km/s/Mpc across the sky seen in multiple datasets, implying that it cannot be measured locally to better than $\sim$ 10% in a model-independent manner.

12 pages, 3 figures, 1 table; Revised and expanded; To appear in CQG; Code available at: https://github.com/rameez3333/SN1aDataandH0

References in corpus (17)

• Large Magellanic Cloud Cepheid Standards Provide a 1% Foundation for the Determination of the Hubble Constant and Stronger Evidence for Physics Beyond LambdaCDM
• Supernova Constraints and Systematic Uncertainties from the First 3 Years of the Supernova Legacy Survey
• TDCOSMO IV: Hierarchical time-delay cosmography -- joint inference of the Hubble constant and galaxy density profiles
• A Test of the Cosmological Principle with Quasars
• Cosmological parameters from the comparison of peculiar velocities with predictions from the 2M++ density field
• Probing cosmic isotropy with a new X-ray galaxy cluster sample through the $L_{\text{X}}-T$ scaling relation
• The Local Perspective on the Hubble Tension: Local Structure Does Not Impact Measurement of the Hubble Constant
• Cosmological implications of the anisotropy of ten galaxy cluster scaling relations
• Early-type Host Galaxies of Type Ia Supernovae. II. Evidence for Luminosity Evolution in Supernova Cosmology
• Anisotropy in the Hubble constant as observed in the HST Extragalactic Distance Scale Key Project results
• Multipole decomposition of the general luminosity distance 'Hubble law' -- a new framework for observational cosmology
• The Hubble constant from eight time-delay galaxy lenses
• Percent-Level Test of Isotropic Expansion Using Type Ia Supernovae
• Luminosity distance and anisotropic sky-sampling at low redshifts: a numerical relativity study
• Effects of Supernova Redshift Uncertainties on the Determination of Cosmological Parameters
• Supernova light-curve fitters and Dark Energy
• Specific Effect of Peculiar Velocities on Dark-Energy Constraints from Type Ia Supernovae

Cited by in corpus (27)

• Challenges for $\Lambda$CDM: An update
• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Is the Observable Universe Consistent with the Cosmological Principle?
• The Pantheon+ Analysis: Improving the Redshifts and Peculiar Velocities of Type Ia Supernovae Used in Cosmological Analyses
• Hints of FLRW Breakdown from Supernovae
• Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies
• An Effective Sign Switching Dark Energy: Lotka-Volterra Model of Two Interacting Fluids
• Cosmological constraints from HII starburst galaxy, quasar angular size, and other measurements
• Dipole Cosmology: The Copernican Paradigm Beyond FLRW
• Resonant neutrino self-interactions and the $H_0$ tension
• Anisotropy in Pantheon+ supernovae
• Electron mass variation from dark sector interactions and compatibility with cosmological observations
• Superhorizon perturbations: A possible explanation of the Hubble--Lemaître Tension and the Large Scale Anisotropy of the Universe
• Moving gravitational wave sources at cosmological distances: Impact on the measurement of the Hubble constant
• Possible Resolution of the Hubble Tension with Weyl Invariant Gravity
• Constraining Exponential f(Q) Gravity with Cosmic Chronometers and Supernovae: A Data-Driven Analysis
• Fitting of supernovae without dark energy
• Cosmological inference from within the peculiar local universe
• Testing inhomogeneous cosmography in our cosmic neighborhood using CosmicFlows-4
• Tilted non-spatially-flat inflation
• Anisotropy in the cosmic acceleration inferred from supernovae
• Evidence for possible systematic underestimation of uncertainties in extragalactic distances and its cosmological implications
• Scalar-tensor cosmologies in a minisuperspace formulation: a case study
• Asymmetry in galaxy spin directions: a fully reproducible experiment using HSC data
• Toward Cosmological Standard Timers in Primordial Black Hole Binaries
• Homology reveals significant anisotropy in the cosmic microwave background
• An effective $\mathbf{\Lambda }$-Szekeres modelling of the local Universe with Cosmicflows-4