Quantifying effects of inhomogeneities and curvature on gravitational wave standard siren measurements of $H(z)$

Abstract

For a flat $\Lambda$CDM universe, the dipole of the luminosity distance can be utilized to measure the Hubble parameter. It is here shown that this is not the case in more general settings where curvature and cosmic backreaction is permitted. This implies that a discordance between $H(z)$ measurements obtained using such dipole luminosity distance data and "true"/actual $H(z)$ data obtained from e.g. cosmic chronometers is a signal of curvature and/or cosmic backreaction. \newline\indent By considering mock future gravitational wave measurements of the Hubble parameter obtained through the dipole luminosity distance, it is shown that already a $1\%$ curvature could in principle just barely show up in the determination. However, for realistic mock data generation using models with as much as 5 \% curvature, parameter estimates do not yield reliable measures of inconsistency between the false $H(z)$ measurements and true measurements of $H(z)$. At the same time, cosmic backreaction is hard to detect even if it makes up $10\%$ of the "energy budget" in the current universe, even when considering a highly idealized situation with low errors. The results concerning backreaction are based on specific "scaling solutions" to the backreaction problem and the study shows that the possibility of detecting a signal of backreaction through the dipole of the luminosity distance depends strongly on the particular backreaction model.

12 pages, 5 figures. Accepted for publication in PRD. v2: Updated reference list and fixed minor typos in text. No changes to results or conclusions

References in corpus (18)

• GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral
• The Clustering of the SDSS DR7 Main Galaxy Sample I: A 4 per cent Distance Measure at z=0.15
• A gravitational-wave standard siren measurement of the Hubble constant
• Planck evidence for a closed Universe and a possible crisis for cosmology
• Cosmic dynamics in the era of Extremely Large Telescopes
• On the evolution of the Hubble constant with the SNe Ia Pantheon Sample and Baryon Acoustic Oscillations: a feasibility study for GRB-cosmology in 2030
• Dipole of the luminosity distance: a direct measure of H(z)
• Correspondence between kinematical backreaction and scalar field cosmologies - the `morphon field'
• On the onset of cosmological backreaction
• Tracing the redshift evolution of Hubble parameter with gravitational-wave standard sirens
• Another look at redshift drift and the backreaction conjecture
• Light propagation in a homogeneous and anisotropic universe
• Searching for signals of inhomogeneity using multiple probes of the cosmic expansion rate H(z)
• Redshift drift in axially symmetric quasi-spherical Szekeres models
• Multipole decomposition of redshift drift -- model independent mapping of the expansion history of the Universe
• Redshift drift in a pressure-gradient cosmology
• Effect of inhomogeneities on the propagation of gravitational waves from binaries of compact objects
• Understanding the Dyer-Roeder approximation as a consequence of local cancellations of projected shear and expansion rate fluctuations

Cited by in corpus (6)

• Null test for cosmic curvature using Gaussian process
• Cosmic backreaction and the mean redshift drift from symbolic regression
• Redshift drift in a universe with structure II: Light rays propagated through a Newtonian N-body simulation
• Future deceleration due to backreaction in a Universe with multiple inhomogeneous domains
• Analyzing the 21-cm signal brightness temperature in the Universe with inhomogeneities
• Constraining the Hubble parameter with the 21 cm brightness temperature signal in a universe with inhomogeneities