Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userThe constraint ability of Hubble parameter by gravitational wave standard sirens on cosmological parameters
151
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
In this paper, we present the application of a new method measuring Hubble parameter $H(z)$ by using the anisotropy of luminosity distance($d_{L}$) of the gravitational wave(GW) standard sirens of neutron star(NS) binary system. The method has never been put into practice so far due to the lack of the ability of detecting GW. However, LIGOs success in detecting GW of black hole(BH) binary system merger announced the potential possibility of this new method. We apply this method to several GW detecting projects, including Advanced LIGO(aLIGO), Einstein Telescope(ET) and DECIGO, and evaluate its constraint ability on cosmological parameters of $H(z)$. It turns out that the $H(z)$ by aLIGO and ET is of bad accuracy, while the $H(z)$ by DECIGO shows a good one. We simulate $H(z)$ data at every 0.1 redshift span using the error information of $H(z)$ by DECIGO, and put the mock data into the forecasting of cosmological parameters. Compared with the previous data and method, we get an obviously tighter constraint on cosmological parameters by mock data, and a concomitantly higher value of Figure of Merit(FoM, the reciprocal of the area enclosed by the $2sigma$ confidence region). For a 3-year-observation by standard sirens of DECIGO, the FoM value is as high as 170.82. If a 10-year-observation is launched, the FoM could reach 569.42. For comparison, the FoM of 38 actual observed $H(z)$ data(OHD) is 9.3. We also investigate the undulant universe, which shows a comparable improvement on the constraint of cosmological parameters. These improvement indicates that the new method has great potential in further cosmological constraints.
rate research
Read More
In this work we investigate the systematic uncertainties that arise from the calculation of the peculiar velocity when estimating the Hubble constant ($H_0$) from gravitational wave standard sirens. We study the GW170817 event and the estimation of the peculiar velocity of its host galaxy, NGC 4993, when using Gaussian smoothing over nearby galaxies. NGC 4993 being a relatively nearby galaxy, at $sim 40 {rm Mpc}$ away, is subject to a significant effect of peculiar velocities. We demonstrate a direct dependence of the estimated peculiar velocity value on the choice of smoothing scale. We show that when not accounting for this systematic, a bias of $sim 200 {rm km s ^{-1}}$ in the peculiar velocity incurs a bias of $sim 4 {rm km s ^{-1} Mpc^{-1}}$ on the Hubble constant. We formulate a Bayesian model that accounts for the dependence of the peculiar velocity on the smoothing scale and by marginalising over this parameter we remove the need for a choice of smoothing scale. The proposed model yields $H_0 = 68.6 ^{+14.0}_{-8.5}~{rm km s^{-1} Mpc^{-1}}$. We demonstrate that under this model a more robust unbiased estimate of the Hubble constant from nearby GW sources is obtained.
We present a detailed study of the methodology for correlating `dark sirens (compact binaries coalescences without electromagnetic counterpart) with galaxy catalogs. We propose several improvements on the current state of the art, and we apply them to the GWTC-2 catalog of LIGO/Virgo gravitational wave (GW) detections, and the GLADE galaxy catalog, performing a detailed study of several sources of systematic errors that, with the expected increase in statistics, will eventually become the dominant limitation. We provide a measurement of $H_0$ from dark sirens alone, finding as the best result $H_0=67.3^{+27.6}_{-17.9},,{rm km}, {rm s}^{-1}, {rm Mpc}^{-1}$ ($68%$ c.l.) which is, currently, the most stringent constraint obtained using only dark sirens. Combining dark sirens with the counterpart for GW170817 we find $H_0= 72.2^{+13.9}_{-7.5} ,{rm km}, {rm s}^{-1}, {rm Mpc}^{-1}$. We also study modified GW propagation, which is a smoking gun of dark energy and modifications of gravity at cosmological scales, and we show that current observations of dark sirens already start to provide interesting limits. From dark sirens alone, our best result for the parameter $Xi_0$ that measures deviations from GR (with $Xi_0=1$ in GR) is $Xi_0=2.1^{+3.2}_{-1.2}$. We finally discuss limits on modified GW propagation under the tentative identification of the flare ZTF19abanrhr as the electromagnetic counterpart of the binary black hole coalescence GW190521, in which case our most stringent result is $Xi_0=1.8^{+0.9}_{-0.6}$. We release the publicly available code $tt{DarkSirensStat}$, which is available under open source license at url{https://github.com/CosmoStatGW/DarkSirensStat}.
LISA and Taiji are expected to form a space-based gravitational-wave (GW) detection network in the future. In this work, we make a forecast for the cosmological parameter estimation with the standard siren observation from the LISA-Taiji network. We simulate the standard siren data based on a scenario with configuration angle of $40^{circ}$ between LISA and Taiji. Three models for the population of massive black hole binary (MBHB), i.e., pop III, Q3d, and Q3nod, are considered to predict the events of MBHB mergers. We find that, based on the LISA-Taiji network, the number of electromagnetic (EM) counterparts detected is almost doubled compared with the case of single Taiji mission. Therefore, the LISA-Taiji networks standard siren observation could provide much tighter constraints on cosmological parameters. For example, solely using the standard sirens from the LISA-Taiji network, the constraint precision of $H_0$ could reach $1.3%$. Moreover, combined with the CMB data, the GW-EM observation based on the LISA-Taiji network could also tightly constrain the equation of state of dark energy, e.g., the constraint precision of $w$ reaches about $4%$, which is comparable with the result of CMB+BAO+SN. It is concluded that the GW standard sirens from the LISA-Taiji network will become a useful cosmological probe in understanding the nature of dark energy in the future.
The observation of binary neutron star merger GW170817, along with its optical counterpart, provided the first constraint on the Hubble constant $H_0$ using gravitational wave standard sirens. When no counterpart is identified, a galaxy catalog can be used to provide the necessary redshift information. However, the true host might not be contained in a catalog which is not complete out to the limit of gravitational-wave detectability. These electromagnetic and gravitational-wave selection effects must be accounted for. We describe and implement a method to estimate $H_0$ using both the counterpart and the galaxy catalog standard siren methods. We perform a series of mock data analyses using binary neutron star mergers to confirm our ability to recover an unbiased estimate of $H_0$. Our simulations used a simplified universe with no redshift uncertainties or galaxy clustering, but with different magnitude-limited catalogs and assumed host galaxy properties, to test our treatment of both selection effects. We explore how the incompleteness of catalogs affects the final measurement of $H_0$, as well as the effect of weighting each galaxys likelihood of being a host by its luminosity. In our most realistic simulation, where the simulated catalog is about three times denser than the density of galaxies in the local universe, we find that a 4.4% measurement precision can be reached using galaxy catalogs with 50% completeness and $sim 250$ binary neutron star detections with sensitivity similar to that of Advanced LIGOs second observing run.
In this work, we use the simulated gravitational wave (GW) standard siren data from the future observation of the Einstein Telescope (ET) to constrain various dark energy cosmological models, including the $Lambda$CDM, $w$CDM, CPL, $alpha$DE, GCG, and NGCG models. We also use the current mainstream cosmological electromagnetic observations, i.e., the cosmic microwave background anisotropies data, the baryon acoustic oscillations data, and the type Ia supernovae data, to constrain these models. We find that the GW standard siren data could tremendously improve the constraints on the cosmological parameters for all these dark energy models. For all the cases, the GW standard siren data can be used to break the parameter degeneracies generated by the current cosmological electromagnetic observational data. Therefore, it is expected that the future GW standard siren observation from the ET would play a crucial role in the cosmological parameter estimation in the future. The conclusion of this work is quite solid because it is based on the analysis for various dark energy models.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
