Matter Dipole and Hubble Tension due to Large Wavelength Perturbations

Abstract

We theoretically analyze the dipole anisotropy observed in the quasar distribution from the CatWISE2020 catalog. The catalog data shows a peak around $z\approx 1$, suggesting the presence of a large-scale dipole component. We explore the possibility that this dipole could be driven by primordial density fluctuations from modes that were superhorizon at the time of CMB decoupling but have since entered the horizon and become subhorizon. In particular, we consider the impact of adiabatic modes with wave numbers $k$ in the range $(10^{-4}-4\times 10^{-3}){\mathrm{Mpc}}^{-1}$, corresponding to wavelength scales of several Gpc. Such modes can create large-scale density variations, likely causing anisotropies in the distribution of matter and, as a result, affecting the number density of observed quasars. We find that these can lead to a significant contribution to the dipole for sources up to redshifts of about 1, but are unable to explain the observed dipole. We also demonstrate that a superhorizon curvature perturbations mode, with a comoving wavenumber $k\lesssim 0.3H_0$ can lead to a significant enhancement in the locally inferred Hubble constant. This effect offers a viable explanation for the observed discrepancy between local and CMB inferred measurements of $H_0$.

11 pages, 6 figures

References in corpus (17)

• 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
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Data Processing, Sky Maps, and Basic Results
• The Sloan Digital Sky Survey Quasar Catalog: Sixteenth Data Release
• The CatWISE2020 Catalog
• A Test of the Cosmological Principle with Quasars
• Is the Observable Universe Consistent with the Cosmological Principle?
• The WISE AGN Catalog
• A Challenge to the Standard Cosmological Model
• Dipoles in the Sky
• Superhorizon Perturbations and the Cosmic Microwave Background
• On Larger $H_0$ Values in the CMB Dipole Direction
• Theoretical systematics in testing the Cosmological Principle with the kinematic quasar dipole
• Explaining Excess Dipole in NVSS Data Using Superhorizon Perturbation
• Alignment of Radio Galaxy Axes using FIRST Catalogue
• Superhorizon perturbations: A possible explanation of the Hubble--Lemaître Tension and the Large Scale Anisotropy of the Universe
• Reassessment of the dipole in the distribution of quasars on the sky
• Probing Cosmology beyond $\Lambda$CDM using the SKA

Cited by in corpus (2)

• The Cosmological Dipole in Tilted Anisotropic Universes
• Cosmic Dipoles from Large-Scale Structure Surveys