Estimating cosmological parameters by the simulated data of gravitational waves from the Einstein Telescope

Abstract

We investigate the constraint ability of the gravitational wave (GW) as the standard siren on the cosmological parameters by using the third-generation gravitational wave detector: the Einstein Telescope. The binary merger of a neutron with either a neutron or black hole is hypothesized to be the progenitor of a short and intense burst of γ rays, some fraction of those binary mergers could be detected both through electromagnetic radiation and gravitational waves. Thus we can determine both the luminosity distance and redshift of the source separately. We simulate the luminosity distances and redshift measurements from 100 to 1000 GW events. We use two different algorithms to constrain the cosmological parameters. For the Hubble constant H0 and dark matter density parameter Ωm, we adopt the Markov chain Monte Carlo approach. We find that with about 500-600 GW events we can constrain the Hubble constant with an accuracy comparable to Planck temperature data and Planck lensing combined results, while for the dark matter density, GWs alone seem not able to provide the constraints as good as for the Hubble constant; the sensitivity of 1000 GW events is a little lower than that of Planck data. It should require more than 1000 events to match the Planck sensitivity. Yet, for analyzing the more complex dynamical property of dark energy, i.e., the equation of state w, we adopt a new powerful nonparametric method: the Gaussian process. We can reconstruct w directly from the observational luminosity distance at every redshift. In the low redshift region, we find that about 700 GW events can give the constraints of w(z) comparable to the constraints of a constant w by Planck data with type Ia supernovae. Those results show that GWs as the standard sirens to probe the cosmological parameters can provide an independent and complementary alternative to current experiments.

Localization of binary neutron star mergers with second and third generation gravitational-wave detectors

“…Einstein Telescope: Various studies have shown that further increase in sensitivity is required for performing precise gravitational wave astronomy, testing of general relativity and improving our understanding of exotic phenomenon like the equation of state and tidal deformability of neutron stars [14,67,[105][106][107]. The Einstein Telescope is a proposed next-generation European gravitational wave observatory [62][63][64] with sensitivity an order of magnitude higher than advanced LIGO and extending down to 1 Hz.…”

Gravity in the infrared and effective nonlocal models

“…This is the origin of the fact that coalescing binaries are 'standard sirens', i.e. their waveform allows a direct reconstruction of the luminosity distance to the source [167][168][169][170][171][172][173][174][175][176][177][178][179]. In GR, for a cosmological model with energy density ρ DE (z), the relation between luminosity distance and redshift is…”

Testing the anisotropy of the universe using the simulated gravitational wave events from advanced LIGO and Virgo

“…In principle, all values of ι ∈ [0 • , 180 • ] are possible. It is pointed out that the maximal effect of inclination angle on the SNR is a factor of 2 [39,44]. Here we only consider the simplified case where the binary's orbital plane is nearly face on, hence the amplitude A is independent of the polarization angle ψ.…”

“…Following Ref. [39], we assume that d L is uncorrelated with that of other parameters and then double the uncertainty of d L calculated from the Fisher matrix as the upper limit of instrument error on d L , i.e.,…”

“…Using the GW/GRB170817 event as standard siren, the Hubble constant is constrained to be 70.0 [34], showing that GW data are very promising in constraining the cosmological parameters. Several works have used the simulated GW data to constrain the cosmological parameters and showed that the constraint ability of GWs is comparable or even better than the traditional probes if hundreds of GW events have been observed [35][36][37][38][39][40].…”