Modified gravitational-wave propagation and standard sirens

By E. Belgacem, Yves Dirian, S. Foffa, M. Maggiore. Physical Review D, 2018

142 citations recorded by the source corpus.

Studies of dark energy at advanced gravitational-wave (GW) interferometers normally focus on the dark energy equation of state $w_{\rm DE}(z)$. However, modified gravity theories that predict a non-trivial dark energy equation of state generically also predict deviations from general relativity in the propagation of GWs across cosmological distances, even in theories where the speed of gravity is equal to $c$. We find that, in generic modified gravity models, the effect of modified GW propagation dominates over that of $w_{\rm DE}(z)$, making modified GW propagation a crucial observable for dark energy studies with standard sirens. We present a convenient parametrization of the effect in terms of two parameters $(\Xi_0,n)$, analogue to the $(w_0,w_a)$ parametrization of the dark energy equation of state, and we give a limit from the LIGO/Virgo measurement of $H_0$ with the neutron star binary GW170817. We then perform a Markov Chain Monte Carlo analysis to estimate the sensitivity of the Einstein Telescope (ET) to the cosmological parameters, including $(\Xi_0,n)$, both using only standard sirens, and combining them with other cosmological datasets. In particular, the Hubble parameter can be measured with an accuracy better than $1\%$ already using only standard sirens while, when combining ET with current CMB+BAO+SNe data, $\Xi_0$ can be measured to $0.8\%$ . We discuss the predictions for modified GW propagation of a specific nonlocal modification of gravity, recently developed by our group, and we show that they are within the reach of ET. Modified GW propagation also affects the GW transfer function, and therefore the tensor contribution to the ISW effect.

Subfields: Astronomy and Astrophysics, Oceanography

View Paper: https://www.semanticscholar.org/paper/d82fa7267c536977caadac3b3e0a2c29f3ef9506

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Oceanography

Citations in the corpus

Dark Energy in Light of Multi-Messenger Gravitational-Wave Astronomy (2018, background): “Introducing a phenomenological parametrization of the GW luminosity distance (Belgacem et al., 2018b)”
Science case for the Einstein telescope (2019, methodology): “1), which would allow us to obtain a measurement of the dark energy equation of state from GW observations [195–197].”
Testing modified gravity at cosmological distances with LISA standard sirens (2019, background): “As discussed in [16], this is a special case of the parametrization (2.”