The Ellipsoidal Universe and the Hubble tension

Abstract

The Hubble tension resides in a statistically significant discrepancy between early time and late time determinations of the Hubble constant. We discuss the Hubble tension within the Ellipsoidal Universe cosmological model. We suggest that allowing small anisotropies in the large-scale spatial geometry could alleviate the tension. We, also, show that the discrepancy in the measurements of the Hubble constant is reduced to a statistically acceptable level if we assume sizeable cosmological anisotropies during the Dark Age. In addition, we argue that the Ellipsoidal Universe cosmological model should resolve the S 8 tension.

Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies

“…This has been investigated [1656], but a single void model cannot give a sufficient contribution to the dipole to account for any mismatch. An interesting relevant "Ellipsoidal Universe" model was originally proposed to address the low quadrupole amplitude in the CMB [1657], but it may also provide an explanation for H 0 and S 8 tensions [1658].…”

CMB two-point angular correlation function in the Ellipsoidal Universe

“…Moreover, we showed that the quadrupole TE and EE correlations in the Ellipsoidal Universe are in reasonable agreement with the Planck 2018 data. Finally, quite recently, we suggested [35] that the Ellipsoidal Universe model should also alleviate the tensions on the Hubble constant H 0 and the cosmological parameter S 8 .…”

Probing the Anisotropic Universe with Gravitational Waves

“…Overall, the errors are consistent with an isotropic Universe, but this exercise can be repeated as GW statistics improve. If the anisotropy is substantiated by both EM and GW events in time, it not only may explain CMB anomalies [8,9,10], but raises a host of interesting theoretical questions [75,76,77,78,79], which can be tested observationally [80,81].…”