The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Xin Zhang - One of the best experts on this subject based on the ideXlab platform.
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prospects for improving cosmological parameter estimation with gravitational wave standard Sirens from taiji
Chinese Science Bulletin, 2020Co-Authors: Ze-wei Zhao, Ling-feng Wang, Jing-fei Zhang, Xin ZhangAbstract:Abstract Taiji, a space-based gravitational-wave observatory, consists of three satellites forming an equilateral triangle with arm length of 3 × 10 6 km, orbiting around the Sun. Taiji is able to observe the gravitational-wave standard siren events of massive black hole binary (MBHB) merger, which is helpful in probing the expansion of the universe. In this paper, we preliminarily forecast the capability of Taiji for improving cosmological parameter estimation with the gravitational-wave standard siren data. We simulate five-year standard siren data based on three fiducial cosmological models and three models of MBHB's formation and growth. It is found that the standard siren data from Taiji can effectively break the cosmological parameter degeneracies generated by the cosmic microwave background (CMB) anisotropies data, especially for dynamical dark energy models. The constraints on cosmological parameters are significantly improved by the data combination CMB + Taiji, compared to the CMB data alone. Compared to the current optical cosmological observations, Taiji can still provide help in improving the cosmological parameter estimation to some extent. In addition, we consider an ideal scenario to investigate the potential of Taiji on constraining cosmological parameters. We conclude that the standard Sirens of MBHB from Taiji will become a powerful cosmological probe in the future.
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prospect for constraining holographic dark energy with gravitational wave standard Sirens from the einstein telescope
European Physical Journal C, 2020Co-Authors: Jing-fei Zhang, Xin Zhang, Hongyan DongAbstract:We study the holographic dark energy (HDE) model by using the future gravitational wave (GW) standard siren data observed from the Einstein Telescope (ET) in this work. We simulate 1000 GW standard siren data based on a 10-year observation of the ET to make this analysis. We find that all the cosmological parameters in the HDE model can be tremendously improved by including the GW standard siren data in the cosmological fit. The GW data combined with the current cosmic microwave background anisotropies, baryon acoustic oscillations, and type Ia supernovae data will measure the cosmological parameters $$\Omega _{\mathrm{m}}$$, $$H_0$$, and c in the HDE model to be at the accuracies of 1.28%, 0.59%, and 3.69%, respectively. A comparison with the cosmological constant model and the constant-w dark energy model shows that, compared to the standard model, the parameter degeneracies will be broken more thoroughly in a dynamical dark energy model. We find that the GW data alone can provide a fairly good measurement for $$H_0$$, but for other cosmological parameters the GW data alone can only provide rather weak measurements. However, due to the fact that the parameter degeneracies can be broken by the GW data, the standard Sirens can play an essential role in improving the parameter estimation.
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Prospects for improving cosmological parameter estimation with gravitational-wave standard Sirens from Taiji
Science Bulletin, 2020Co-Authors: Ze-wei Zhao, Ling-feng Wang, Jing-fei Zhang, Xin ZhangAbstract:Taiji, a space-based gravitational-wave observatory, consists of three satellites forming an equilateral triangle with arm length of $3\times 10^6$ km, orbiting around the Sun. Taiji is able to observe the gravitational-wave standard siren events of massive black hole binary (MBHB) merger, which is helpful in probing the expansion of the universe. In this paper, we preliminarily forecast the capability of Taiji for improving cosmological parameter estimation with the gravitational-wave standard siren data. We simulate five-year standard siren data based on three fiducial cosmological models and three models of MBHB's formation and growth. It is found that the standard siren data from Taiji can effectively break the cosmological parameter degeneracies generated by the cosmic microwave background (CMB) anisotropies data, especially for dynamical dark energy models. The constraints on cosmological parameters are significantly improved by the data combination CMB+Taiji, compared to the CMB data alone. Compared to the current optical cosmological observations, Taiji can still provide help in improving the cosmological parameter estimation to some extent. In addition, we consider an ideal scenario to investigate the potential of Taiji on constraining cosmological parameters. We conclude that the standard Sirens of MBHB from Taiji will become a powerful cosmological probe in the future.
Hsinyu Chen - One of the best experts on this subject based on the ideXlab platform.
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systematic uncertainty of standard Sirens from the viewing angle of binary neutron star inspirals
Physical Review Letters, 2020Co-Authors: Hsinyu ChenAbstract:The independent measurement of the Hubble constant with gravitational-wave standard Sirens will potentially shed light on the tension between the local distance ladders and Planck experiments. Therefore, thorough understanding of the sources of systematic uncertainty for the standard siren method is crucial. In this Letter, we focus on two scenarios that will potentially dominate the systematic uncertainty of standard Sirens. First, simulations of electromagnetic counterparts of binary neutron star mergers suggest aspherical emissions, so the binaries available for the standard siren method can be selected by their viewing angles. This selection effect can lead to $\ensuremath{\gtrsim}2%$ bias in Hubble constant measurement even with mild selection. Second, if the binary viewing angles are constrained by the electromagnetic counterpart observations but the bias of the constraints is not controlled under $\ensuremath{\sim}10\ifmmode^\circ\else\textdegree\fi{}$, the resulting systematic uncertainty in the Hubble constant will be $g3%$. In addition, we find that both of the systematics cannot be properly removed by the viewing angle measurement from gravitational-wave observations. Comparing to the known dominant systematic uncertainty for standard Sirens, the $\ensuremath{\le}2%$ gravitational-wave calibration uncertainty, the effects from the viewing angle appear to be more significant. Therefore, the systematic uncertainty from the viewing angle might be a major challenge before the standard Sirens can resolve the tension in the Hubble constant, which is currently $\ensuremath{\sim}9%$.
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Precision standard siren cosmology
2017Co-Authors: Hsinyu Chen, Maya Fishbach, Daniel E HolzAbstract:We discuss the constraints on the Hubble constant to be expected from standard siren sources in ground-based gravitational wave detectors. We consider binary neutron star and binary black hole sources, and focus on the role of golden Sirens (the loudest and best constrained sources) to constrain cosmological parameters. We consider two approaches: the counterpart case, where electromagnetic observations provide an independent measurement of the redshift to the sources, and the statistical case, incorporating an analysis over all potential host galaxies within the localization volumes. Our analysis includes realistic measurement uncertainties and selection biases. Although the specific results depend on the configuration and sensitivity of the detector networks, we find that the statistical method would constrain $H_0$ to $4\%$ with $\sim100$ detections of binary neutron star mergers, while an equivalent statistical measurement can be accomplished with $\sim30$ golden events (all fractional uncertainties are quoted as half of the width of the symmetric 68% credible interval divided by the median of the $H_0$ posterior). Alternatively, with $\sim10/60/200$ binary neutron star standard Sirens with electromagnetic counterparts, $H_0$ would be constrained to $4/2/1\%$. Given current rate uncertainties, the 5% measurement may happen within the 9 month O3 LIGO/Virgo run (starting Fall 2018), or if the rate is low this may not happen until one full year of the LIGO/Virgo network at design sensitivity (starting $\sim$2021+). Similarly, the 1% measurement may happen within two years of running at design sensitivity ($\sim$2024+), or may not happen until 3+ years of operation of a full five-detector network. Although the rates, and thus precise timetable, remain uncertain, precision standard siren cosmology can be expected in the foreseeable future.
John E Fauth - One of the best experts on this subject based on the ideXlab platform.
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Identifying potential keystone species from field data – an example from temporary ponds
Ecology Letters, 2002Co-Authors: John E FauthAbstract:Identifying keystone species is essential for understanding community dynamics and preserving species richness. However, few studies have used quantitative, a priori methods to identify potential keystone species. Species known to act as keystones in North Carolina (NC) temporary ponds (Notophthalmus viridescens, eastern newt, and Siren intermedia, lesser siren) were tested to see whether they played the same role in similar habitats in South Carolina (SC). Newts and Sirens had no effect on anuran species richness in SC. Instead, another salamander (Ambystoma talpoideum, mole salamander) absent from the NC ponds was identified as a strong keystone in SC. It functioned independently of environmental factors and the densities of other predators. Larval dragonflies (Tramea carolina, Carolina saddlebag) were identified as weak, context-dependent keystones in SC, supporting anuran richness in isolated ponds with very low pH. The results suggest that the identity of keystone species varies, even in similar habitats within a physiographic region.
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Interactions between branchiate mole salamanders (Ambystoma talpoideum) and lesser Sirens (Siren intermedia): asymmetrical competition and intraguild predation
Amphibia-Reptilia, 1999Co-Authors: John E FauthAbstract:Using field sampling and experiments in natural and artificial ponds, I studied interactions between branchiate adult mole salamanders (Ambystoma talpoideum) and lesser Sirens (Siren intermedia), two top predators in temporary ponds of the southeastern United States. The abundance and distribution of these two salamanders were independent among ponds, with A. talpoideum more numerous and widespread than S. intermedia. Both species were more likely to be found in ponds near other intermittent wetlands. Within a pond, captures of these two species were negatively correlated, and a field experiment showed that paedomorphic A. talpoideum avoided traps containing S. intermedia. An experiment in artificial ponds confirmed that interactions between these two species were highly asymmetrical; S. intermedia reduced the growth and recruitment of A. talpoideum without experiencing reciprocal. positive or negative effects. These results suggest that S. intermedia competes with and is an intraguild predator of A. talpoideum, limiting its growth and controlling its recruitment.
Jing-fei Zhang - One of the best experts on this subject based on the ideXlab platform.
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prospects for improving cosmological parameter estimation with gravitational wave standard Sirens from taiji
Chinese Science Bulletin, 2020Co-Authors: Ze-wei Zhao, Ling-feng Wang, Jing-fei Zhang, Xin ZhangAbstract:Abstract Taiji, a space-based gravitational-wave observatory, consists of three satellites forming an equilateral triangle with arm length of 3 × 10 6 km, orbiting around the Sun. Taiji is able to observe the gravitational-wave standard siren events of massive black hole binary (MBHB) merger, which is helpful in probing the expansion of the universe. In this paper, we preliminarily forecast the capability of Taiji for improving cosmological parameter estimation with the gravitational-wave standard siren data. We simulate five-year standard siren data based on three fiducial cosmological models and three models of MBHB's formation and growth. It is found that the standard siren data from Taiji can effectively break the cosmological parameter degeneracies generated by the cosmic microwave background (CMB) anisotropies data, especially for dynamical dark energy models. The constraints on cosmological parameters are significantly improved by the data combination CMB + Taiji, compared to the CMB data alone. Compared to the current optical cosmological observations, Taiji can still provide help in improving the cosmological parameter estimation to some extent. In addition, we consider an ideal scenario to investigate the potential of Taiji on constraining cosmological parameters. We conclude that the standard Sirens of MBHB from Taiji will become a powerful cosmological probe in the future.
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prospect for constraining holographic dark energy with gravitational wave standard Sirens from the einstein telescope
European Physical Journal C, 2020Co-Authors: Jing-fei Zhang, Xin Zhang, Hongyan DongAbstract:We study the holographic dark energy (HDE) model by using the future gravitational wave (GW) standard siren data observed from the Einstein Telescope (ET) in this work. We simulate 1000 GW standard siren data based on a 10-year observation of the ET to make this analysis. We find that all the cosmological parameters in the HDE model can be tremendously improved by including the GW standard siren data in the cosmological fit. The GW data combined with the current cosmic microwave background anisotropies, baryon acoustic oscillations, and type Ia supernovae data will measure the cosmological parameters $$\Omega _{\mathrm{m}}$$, $$H_0$$, and c in the HDE model to be at the accuracies of 1.28%, 0.59%, and 3.69%, respectively. A comparison with the cosmological constant model and the constant-w dark energy model shows that, compared to the standard model, the parameter degeneracies will be broken more thoroughly in a dynamical dark energy model. We find that the GW data alone can provide a fairly good measurement for $$H_0$$, but for other cosmological parameters the GW data alone can only provide rather weak measurements. However, due to the fact that the parameter degeneracies can be broken by the GW data, the standard Sirens can play an essential role in improving the parameter estimation.
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Prospects for improving cosmological parameter estimation with gravitational-wave standard Sirens from Taiji
Science Bulletin, 2020Co-Authors: Ze-wei Zhao, Ling-feng Wang, Jing-fei Zhang, Xin ZhangAbstract:Taiji, a space-based gravitational-wave observatory, consists of three satellites forming an equilateral triangle with arm length of $3\times 10^6$ km, orbiting around the Sun. Taiji is able to observe the gravitational-wave standard siren events of massive black hole binary (MBHB) merger, which is helpful in probing the expansion of the universe. In this paper, we preliminarily forecast the capability of Taiji for improving cosmological parameter estimation with the gravitational-wave standard siren data. We simulate five-year standard siren data based on three fiducial cosmological models and three models of MBHB's formation and growth. It is found that the standard siren data from Taiji can effectively break the cosmological parameter degeneracies generated by the cosmic microwave background (CMB) anisotropies data, especially for dynamical dark energy models. The constraints on cosmological parameters are significantly improved by the data combination CMB+Taiji, compared to the CMB data alone. Compared to the current optical cosmological observations, Taiji can still provide help in improving the cosmological parameter estimation to some extent. In addition, we consider an ideal scenario to investigate the potential of Taiji on constraining cosmological parameters. We conclude that the standard Sirens of MBHB from Taiji will become a powerful cosmological probe in the future.
Stanley E. Trauth - One of the best experts on this subject based on the ideXlab platform.
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Seasonal Activity, Population Characteristics, and Age Estimation in the Aquatic Salamander, Siren intermedia nettingi (Goin)
Journal of the Arkansas Academy of Science, 2011Co-Authors: J. A. Sawyer, Stanley E. TrauthAbstract:We conducted a study of the Western Lesser Siren (Siren intermedia nettinigi), at a locality termed the Airport Road site in Jonesboro (Craighead County, AR) from November 2004 until March 2007. This site consisted of a network of roadside ditches in cultivated lawns in an industrial park. Even though Sirens are known to occur frequently in ditches, most studies of the genus Siren have taken place in natural wetlands. We compiled mark-recapture data at the Airport Road site for each season to determine if the seasonal activity pattern for Sirens in northeast Arkansas varied from activity data previously published from other localities in the range of this species. Capture rates were higher in the fall and spring. The predicted overall population size was 110 Sirens at a density of 0.81 Sirens per linear m. This density was less than the densities (in Sirens/m 2 ) reported by previous studies. We found two prominent peaks in Sirens per size class: the first at 161-170 mm, and the second at 201-210 mm. Other researchers have assumed that the two most abundant size classes in siren populations represent one-year-old and two-year-old cohorts. The Sirens captured at the Airport Road site are smaller, on average, than those reported in previous population studies. We found no significant difference between the growth rates of Sirens larger than 200 mm SVL and those smaller than 200 mm snout-vent length (= SVL; P = 0.957, confidence interval -1.945, 2.045, n = 16). Our mean growth rates did not significantly differ from growth rates reported for Sirens elsewhere. We sectioned siren humeri to identify and quantify lines of arrested growth (LAGs) as part of a skeletochronological analysis. The use of SVL was a poor indicator of number of LAGs. The difference in the weather pattern history in each of the voucher Sirens used likely resulted in broad ranges of LAGs for each SVL size class.
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Helminths of the western lesser siren, Siren intermedia nettingi (Caudata: Sirenidae), from Arkansas
Journal of the Helminthological Society of Washington, 1994Co-Authors: Chris T Mcallister, Stanley E. Trauth, Stephen R. Goldberg, Charles R. Bursey, H. J. Holshuh, B. G. CochranAbstract:Sixteen juvenile and adult western lesser Sirens, Siren intermedia nettingi Goin, 1942, were col- lected from 2 counties in Arkansas and examined for endoparasites. Eleven (69%) Sirens harbored 1 or more parasites, including 1 (6%) with Diplostomum sp. meta- cercariae, 9 (56%) with Proteocephalus sireni, 1 (6%) with larval Capillaria sp., and 2 (13%) with Falcaustra chabaudi. New locality records are documented for P. sireni and F. chabaudi, and new host records are reported for Diplostomum sp. and Capillaria sp. The histopathology of the larval Capillaria integumental infection is described in the new host. A summary is provided on helminths of Siren spp.