Searching for signals of inhomogeneity using multiple probes of the cosmic expansion rate H(z)

Abstract

It is argued that cosmic chronometers yield estimates of the spatially averaged expansion rate even in a universe that is not well described by a global FLRW model - as long as the Universe is statistically homogeneous and isotropic with a sufficiently small homogeneity scale. On the other hand, measurements of the expansion rate based on observations of redshift drift will not in general yield estimates of the spatially averaged expansion rate - but it will in the case where the universe is described well by a single FLRW model on large scales. Therefore, a disagreement between measurements of the expansion rate based on cosmic chronometers versus redshift drift is an expected signal of non-negligible cosmic backreaction.

6 pages, 2 captioned figures. Accepted for publication in PRL

References in corpus (13)

• Raising the bar: new constraints on the Hubble parameter with cosmic chronometers at z$\sim$2
• Planck evidence for a closed Universe and a possible crisis for cosmology
• Cosmic dynamics in the era of Extremely Large Telescopes
• A general test of the Copernican Principle
• Dipole of the luminosity distance: a direct measure of H(z)
• Exploring the Dark Energy Redshift Desert with the Sandage-Loeb Test
• Tracing the redshift evolution of Hubble parameter with gravitational-wave standard sirens
• Another look at redshift drift and the backreaction conjecture
• Accelerated expansion without dark energy
• Does small scale structure significantly affect cosmological dynamics?
• Multipole decomposition of redshift drift -- model independent mapping of the expansion history of the Universe
• Constraining Models of Dark Energy
• Real time cosmology - A direct measure of the expansion rate of the Universe

Cited by in corpus (5)

• Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies
• Backreaction in Cosmology
• Quantifying effects of inhomogeneities and curvature on gravitational wave standard siren measurements of $H(z)$
• Redshift drift in a universe with structure II: Light rays propagated through a Newtonian N-body simulation
• Multiple measurements on the cosmic curvature using Gaussian process regression without calibration and a cosmological model