Improving cosmological parameter estimation with the future gravitational-wave standard siren observation from the Einstein Telescope

Abstract

Detection of gravitational waves produced by merger of binary compact objects could provide an independent way for measuring the luminosity distance to the gravitational-wave burst source, indicating that gravitational-wave observation, combined with observation of electromagnetic counterparts, can provide "standard sirens" for investigating the expansion history of the universe in cosmology. In this work, we wish to investigate how the future gravitational-wave standard siren observations would break the parameter degeneracies existing in the conventional optical observations and how they help improve the parameter estimation in cosmology. We take the third-generation ground-based gravitational-wave detector, the Einstein Telescope, as an example to make an analysis. By simulating 1000 events data in the redshift range between 0 and 5 based on the ten-year observation of the Einstein Telescope, we find that the gravitational-wave data could largely break the degeneracy between the matter density and the Hubble constant, thus significantly improving the cosmological constraints. We further show that the constraint on the equation-of-state parameter of dark energy could also be significantly improved by including the gravitational-wave data in the cosmological fit.

Prospect for constraining holographic dark energy with gravitational wave standard sirens from the Einstein Telescope

“…It is found in Ref. [60] that the standard sirens are fairly good at measuring the Hubble constant, but for the measurements of other cosmological parameters they are actually not so good. It is shown in Ref.…”

“…It is shown in Ref. [60] that the measurement of H 0 by GW alone is at a 0.3% precision for the ΛCDM model, and a 0.5% precision for the wCDM model. The most important finding in Ref.…”

“…The most important finding in Ref. [60] is that the GW standard sirens can be used to break the parameter degeneracies formed by other observations. This is because the standard sirens can measure the absolute luminosity distance.…”

Gravitational wave standard sirens and cosmological parameter measurement

“…In Ref. [13], we show that the measurement of H 0 by GW alone is at a 0.3% precision for ΛCDM and at a 0.5% precision for wCDM. Because the standard sirens can measure the absolute luminosity distance, they can break the parameter degeneracies formed by other observations.…”

Future constraints on dynamical dark-energy using gravitational-wave standard sirens

“…Here, considering these four well known dark energy parametrzations, namely, CPL, Logarithmic, JBP and BA, we perform a robust analysis by constraining their parameter space using the simulated GW data from the Einstein Telescope along with the standard astronomical probes such as cosmic microwave background radiation (CMB) [49,50], baryon acoustic oscillations (BAO) [51][52][53], Supernove Type Ia (SNIa) [54] and Hubble parameter measurements from the cosmic chronometers (CC) [55], in order to see how the data from GW improve the parameter space of these known parametrizations compared to their usual cosmological constraints availed from the known cosmological probes, CMB, BAO, SNIa and CC. We refer to some earlier works on dark energy with similar motivation, that means where the simulated GW data from the Einstein Telescope were taken into account [56][57][58][59][60][61]. We mention that it will be also interesting to use simulated GW data from other observatories like Laser Interferometer Space Antenna (LISA) [70], Deci-hertz Interferometer Gravitational wave Observatory (DECIGO) [71,72], TianQin [73].…”