Percent-Level Test of Isotropic Expansion Using Type Ia Supernovae

Abstract

We propose and implement a novel, robust, and non-parametric test of statistical isotropy of the expansion of the universe, and apply it to around one thousand type Ia supernovae from the Pantheon sample. We calculate the angular clustering of supernova magnitude residuals and compare it to the noise expected under the isotropic assumption. We also test for systematic effects and demonstrate that their effects are negligible or are already accounted for in our procedure. We express our constraints as an upper limit on the rms spatial variation in the Hubble parameter at late times. For the sky smoothed with a Gaussian with fwhm=60 deg, less than 1% rms spatial variation in the Hubble parameter is allowed at 99.7% confidence.

5 pages, 4 figures

References in corpus (8)

• Inflationary Universe with Anisotropic Hair
• Correcting Type Ia Supernova Distances for Selection Biases and Contamination in Photometrically Identified Samples
• Cosmic Microwave Background Statistics for a Direction-Dependent Primordial Power Spectrum
• Dipole of the luminosity distance: a direct measure of H(z)
• Testing the Isotropy of the Universe with Type Ia Supernovae
• Probing Dark Energy Anisotropy
• Probing bulk flow with nearby SNe Ia data
• Testing the isotropy of the Universe with type Ia supernovae in a model-independent way

Cited by in corpus (22)

• The Pantheon+ Analysis: Cosmological Constraints
• Cosmological implications of the anisotropy of ten galaxy cluster scaling relations
• Testing spatial curvature and anisotropic expansion on top of the $\Lambda$CDM model
• Is there really a Hubble tension?
• Screening anisotropy via energy-momentum squared gravity: $\Lambda$CDM model with hidden anisotropy
• The quadrupole in the local Hubble parameter: first constraints using Type Ia supernova data and forecasts for future surveys
• Anisotropic constant-roll inflation for the Dirac-Born-Infeld model
• Anisotropic universe with anisotropic dark energy
• Anisotropic power-law inflation for a model of two scalar and two vector fields
• Stable small spatial hairs in a power-law k-inflation model
• On the cosmological performance of photometrically classified supernovae with machine learning
• Comprehensive Constraints on Dark Radiation Injection After BBN
• Anisotropic hyperbolic inflation for a model of two scalar and two vector fields
• Concerns about the reliability of publicly available SNe Ia data
• Examining the local Universe isotropy with galaxy cluster velocity dispersion scaling relations
• The Next Generation of Cosmological Measurements with Type Ia Supernovae
• $\Lambda$CDM cosmology with a quiescent anisotropy in a higher dimensional steady state universe
• A probabilistic framework for cosmological inference of peculiar velocities
• New Constraints on Anisotropic Expansion from Supernovae Type Ia
• A Quantitative Framework for Testing the Hubble Tension in a Bianchi Type I Cosmological Background
• Lorentzian Vacuum Transitions for Anisotropic Universes
• Anisotropic constant-roll k-inflation model