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Li, Tian-Nuo, Shang-Jie Jin, Hai-Li Li, Jing-Fei Zhang i Xin Zhang. "Prospects for Probing the Interaction between Dark Energy and Dark Matter Using Gravitational-wave Dark Sirens with Neutron Star Tidal Deformation". Astrophysical Journal 963, nr 1 (28.02.2024): 52. http://dx.doi.org/10.3847/1538-4357/ad1bc9.
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Abstract Gravitational wave (GW) standard siren observations provide a rather useful tool to explore the evolution of the Universe. In this work, we wish to investigate whether dark sirens with neutron star (NS) deformation from third-generation GW detectors could help probe the interaction between dark energy and dark matter. We simulate the GW dark sirens of four detection strategies based on 3 yr observation and consider four phenomenological interacting dark energy (IDE) models to perform cosmological analysis. We find that GW dark sirens could provide tight constraints on Ωm and H 0 in the four IDE models but do not perform well in constraining the dimensionless coupling parameter β in models of the interaction proportional to the energy density of cold dark matter. Nevertheless, the parameter degeneracy orientations of cosmic microwave background (CMB) and GW are almost orthogonal, and thus, the combination of them could effectively break cosmological parameter degeneracies, with the constraint errors of β being 0.00068–0.018. In addition, we choose three typical equations of state (EoSs) of an NS, i.e., SLy, MPA1, and MS1, to investigate the effect of an NS’s EoS on cosmological analysis. The stiffer EoS could give tighter constraints than the softer EoS. Nonetheless, the combination of CMB and GW dark sirens (using different EoSs of an NS) shows basically the same constraint results of cosmological parameters. We conclude that the dark sirens from 3G GW detectors would play a crucial role in helping probe the interaction between dark energy and dark matter, and the CMB+GW results are basically not affected by the EoS of an NS.
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Zhu, Liang-Gui, i Xian Chen. "The Dark Side of Using Dark Sirens to Constrain the Hubble–Lemaître Constant". Astrophysical Journal 948, nr 1 (1.05.2023): 26. http://dx.doi.org/10.3847/1538-4357/acc24b.
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Abstract Dark sirens, i.e., gravitational-wave (GW) sources without electromagnetic counterparts, are new probes of the expansion of the universe. The efficacy of this method relies on correctly localizing the host galaxies. However, recent theoretical studies have shown that astrophysical environments could mislead the spatial localization by distorting the GW signals. It is unclear whether and to what degree the incorrect spatial localizations of dark sirens would impair the accuracy of the measurement of the cosmological parameters. To address this issue, we consider the future observations of dark sirens using the Cosmic Explorer and the Einstein Telescope, and we design a Bayesian framework to access the precision of measuring the Hubble–Lemaître constant H 0. Interestingly, we find that the precision is not compromised when the number of well-localized dark sirens is significantly below 300, even in the extreme scenario that all the dark sirens are localized incorrectly. As the number exceeds 300, the incorrect spatial localizations start to produce statistically noticeable effects, such as a slow convergence of the posterior distribution of H 0. We propose several tests that can be used in future observations to verify the spatial localizations of dark sirens. Simulations of these tests suggest that incorrect spatial localizations will dominate a systematic error of H 0 if as much as 10% of a sample of 300 well-localized dark sirens are affected by their environments. Our results have important implications for the long-term goal of measuring H 0 to a precision of <1% using dark sirens.
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Palmese, A., C. R. Bom, S. Mucesh i W. G. Hartley. "A Standard Siren Measurement of the Hubble Constant Using Gravitational-wave Events from the First Three LIGO/Virgo Observing Runs and the DESI Legacy Survey". Astrophysical Journal 943, nr 1 (1.01.2023): 56. http://dx.doi.org/10.3847/1538-4357/aca6e3.
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Abstract We present a new constraint on the Hubble constant H 0 using a sample of well-localized gravitational-wave (GW) events detected during the first three LIGO/Virgo observing runs as dark standard sirens. In the case of dark standard sirens, a unique host galaxy is not identified, and the redshift information comes from the distribution of potential host galaxies. From the third LIGO/Virgo observing run detections, we add the asymmetric-mass binary black hole GW190412 and the high-confidence GW candidates S191204r, S200129m, and S200311bg to the sample of dark standard sirens analyzed in Palmese et al. Our sample contains the top 20% (based on localization) GW events and candidates to date with significant coverage by the Dark Energy Spectroscopic Instrument Legacy Survey. We combine the H 0 posterior for eight dark siren events, finding H 0 = 79.8 − 12.8 + 19.1 km s − 1 Mpc − 1 (68% highest density interval) for a prior in H 0 uniform between [20, 140] km s−1 Mpc−1. This result shows that a combination of eight well-localized dark sirens combined with an appropriate galaxy catalog is able to provide an H 0 constraint that is competitive (∼20% versus 18% precision) with a single bright standard siren analysis (i.e., assuming the electromagnetic counterpart) using GW170817. When combining the posterior with that from GW170817, we obtain H 0 = 72.77 − 7.55 + 11.0 km s − 1 Mpc − 1 . This result is broadly consistent with recent H 0 estimates from both the cosmic microwave background and supernovae.
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Jin, Shang-Jie, Tian-Nuo Li, Jing-Fei Zhang i Xin Zhang. "Prospects for measuring the Hubble constant and dark energy using gravitational-wave dark sirens with neutron star tidal deformation". Journal of Cosmology and Astroparticle Physics 2023, nr 08 (1.08.2023): 070. http://dx.doi.org/10.1088/1475-7516/2023/08/070.
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Abstract Using the measurements of tidal deformation in the binary neutron star (BNS) coalescences can obtain the information of redshifts of gravitational wave (GW) sources, and thus actually the cosmic expansion history can be investigated using solely such GW dark sirens. To do this, the key is to get a large number of accurate GW data, which can be achieved with the third-generation (3G) GW detectors. Here we wish to offer an answer to the question of whether the Hubble constant and the equation of state (EoS) of dark energy can be precisely measured using solely GW dark sirens. We find that in the era of 3G GW detectors 𝒪(105 – 106) dark siren data (with the NS tidal measurements) could be obtained in three-year observation if the EoS of NS is perfectly known, and thus using only dark sirens can actually achieve the precision cosmology. Based on a network of 3G detectors, we obtain the constraint precisions of 0.15% and 0.95% for the Hubble constant H 0 and the constant EoS of dark energy w, respectively; for a two-parameter EoS parametrization of dark energy, the precision of w 0 is 2.04% and the error of wa is 0.13. We conclude that 3G GW detectors would lead to breakthroughs in solving the Hubble tension and revealing the nature of dark energy provided that the EoS of NS is perfectly known.
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Jin, Shang-Jie, Rui-Qi Zhu, Ji-Yu Song, Tao Han, Jing-Fei Zhang i Xin Zhang. "Standard siren cosmology in the era of the 2.5-generation ground-based gravitational wave detectors: bright and dark sirens of LIGO Voyager and NEMO". Journal of Cosmology and Astroparticle Physics 2024, nr 08 (1.08.2024): 050. http://dx.doi.org/10.1088/1475-7516/2024/08/050.
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Abstract The 2.5-generation (2.5G) ground-based gravitational wave (GW) detectors LIGO Voyager and NEMO are expected to be operational in the late 2020s and early 2030s. In this work, we explore the potential of GW standard sirens observed by the 2.5G GW detectors in measuring cosmological parameters, especially for the Hubble constant. Using GWs to measure cosmological parameters is inherently challenging, especially for 2.5G detectors, given their limited capability, which results in weaker constraints on cosmological parameters from the detected standard sirens. However, the measurement of the Hubble constant using standard siren observations from Voyager and NEMO is still promising. For example, using bright sirens from Voyager and NEMO can measure the Hubble constant with a precision of about 2% and 6% respectively, and using the Voyager-NEMO network can improve the precision to about 1.6%. Moreover, bright sirens can be used to break the degeneracy of cosmological parameters generated by CMB data, and to a certain extent, 2.5G detectors can also play a role in this aspect. Observations of dark sirens by 2.5G detectors can achieve relatively good results in measuring the Hubble constant, with a precision of within 2%, and if combining observations of bright and dark sirens, the precision of the Hubble constant measurement can reach about 1.4%. Finally, we also discussed the impact of the uncertainty in the binary neutron star merger rate on the estimation of cosmological parameters. We conclude that the magnificent prospect for solving the Hubble tension is worth expecting in the era of the 2.5G ground-based GW detectors.
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Cai, Rong-Gen, i Tao Yang. "Standard sirens and dark sector with Gaussian process". EPJ Web of Conferences 168 (2018): 01008. http://dx.doi.org/10.1051/epjconf/201816801008.
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The gravitational waves from compact binary systems are viewed as a standard siren to probe the evolution of the universe. This paper summarizes the potential and ability to use the gravitational waves to constrain the cosmological parameters and the dark sector interaction in the Gaussian process methodology. After briefly introducing the method to reconstruct the dark sector interaction by the Gaussian process, the concept of standard sirens and the analysis of reconstructing the dark sector interaction with LISA are outlined. Furthermore, we estimate the constraint ability of the gravitational waves on cosmological parameters with ET. The numerical methods we use are Gaussian process and the Markov-Chain Monte-Carlo. Finally, we also forecast the improvements of the abilities to constrain the cosmological parameters with ET and LISA combined with the Planck.
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Dalang, Charles, i Tessa Baker. "The clustering of dark sirens' invisible host galaxies". Journal of Cosmology and Astroparticle Physics 2024, nr 02 (1.02.2024): 024. http://dx.doi.org/10.1088/1475-7516/2024/02/024.
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Abstract Dark sirens are a powerful way to infer cosmological and astrophysical parameters from the combination of gravitational wave sirens and galaxy catalogues. Importantly, the method relies on the completeness of the galaxy catalogues being well modelled. A magnitude-limited catalogue will always be incomplete to some extent, requiring a completion scheme to avoid biasing the parameter inference. Standard methods include homogeneous and multiplicative completion, which have the advantage of simplicity but underestimate or overestimate the amplitude of structure at low completeness, respectively. In this work, we propose a new method to complete galaxy catalogues which uses clustering information to incorporate knowledge of the large scale structure into the dark sirens method. We find that if the structure of the true number of galaxies is sufficiently well preserved in the catalogue, our estimator can perform drastically better than both homogeneous and multiplicative completion. We lay the foundations for a maximally informative dark sirens analysis and discuss its limitations.
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Hou, Wan-Ting, Jing-Zhao Qi, Tao Han, Jing-Fei Zhang, Shuo Cao i Xin Zhang. "Prospects for constraining interacting dark energy models from gravitational wave and gamma ray burst joint observation". Journal of Cosmology and Astroparticle Physics 2023, nr 05 (1.05.2023): 017. http://dx.doi.org/10.1088/1475-7516/2023/05/017.
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Abstract With the measurement of the electromagnetic (EM) counterpart, a gravitational wave (GW) event could be treated as a standard siren. As a novel cosmological probe, GW standard sirens will bring significant implications for cosmology. In this paper, by considering the coincident detections of GW and associated γ ray burst (GRB), we find that only about 400 GW bright standard sirens from binary neutron star mergers could be detected in a 10-year observation of the Einstein Telescope and the THESEUS satellite mission. Based on this mock sample, we investigate the implications of GW standard sirens on the interaction between dark energy and dark matter. In our analysis, four viable interacting dark energy (IDE) models, with interaction forms Q = 3βHρ de and Q = Q = 3βHρ c, are considered. Compared with the traditional EM observational data such as CMB, BAO, and SN Ia, the combination of both GW and EM observations could effectively break the degeneracies between different cosmological parameters and provide more stringent cosmological fits. We find that the GW data could play a more important role for determining the interaction in the models with Q = 3βHρ c, compared with the models with Q = 3βHρ de. We also show that constraining IDE models with mock GW data based on different fiducial H 0 values yield different results, indicating that accurate determination of H 0 is significant for exploring the interaction between dark energy and dark matter.
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Zhang, Pengjie, i Hai Yu. "Calibrating systematic errors in the distance determination with the luminosity–distance space large-scale structure of dark sirens and its potential applications". Monthly Notices of the Royal Astronomical Society 507, nr 3 (14.08.2021): 3381–86. http://dx.doi.org/10.1093/mnras/stab2329.
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ABSTRACT The cosmological luminosity–distance can be measured from gravitational wave (GW) standard sirens, free of astronomical distance ladders, and the associated systematics. However, it may still contain systematics arising from various astrophysical, cosmological, and experimental sources. With the large amount of dark standard sirens of upcoming third generation GW experiments, such potential systematic bias, can be diagnosed and corrected by statistical tools of the large-scale structure of the universe. We estimate that, by cross-correlating the dark siren luminosity–distance space distribution and galaxy redshift space distribution, multiplicative error m in the luminosity distance measurement can be constrained with 1σ uncertainty σm ∼ 0.1. This is already able to distinguish some binary black hole origin scenarios unambiguously. Significantly better constraints and therefore more applications may be achieved by more advanced GW experiments.
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Yang, Tao, Hyung Mok Lee, Rong-Gen Cai, Han Gil Choi i Sunghoon Jung. "Space-borne atom interferometric gravitational wave detections. Part II. Dark sirens and finding the one". Journal of Cosmology and Astroparticle Physics 2022, nr 01 (1.01.2022): 042. http://dx.doi.org/10.1088/1475-7516/2022/01/042.
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Abstract In this paper, we investigate the potential of dark sirens by the space-borne atom interferometric gravitational-wave detectors to probe the Hubble constant. In the mid-frequency band, the sources live a long time. The motion of a detector around the Sun as well as in Earth orbit would induce large Doppler and reorientation effects, providing a precise angular resolution. Such precise localization for the GW sources makes it possible to observe the dark sirens with only one potential host galaxy, which are dubbed “golden dark sirens”. We construct the catalogs of golden dark sirens and estimate that there are around 79 and 35 golden dark sirens of binary neutron stars (BNS) and binary black holes (BBH) that would be pass the detection threshold of AEDGE in 5 years. Our results show that with 5, 10, and all 79 golden dark BNS tracked by AEDGE one can constrain H 0 at 5.5%, 4.1%, and 1.8% precision levels. With 5, 10, and all 35 golden dark BBH one can constrain H 0 at 2.2%, 1.8%, and 1.5% precision levels, respectively. It suggests that only 5–10 golden dark BBH by AEDGE are sufficient to arbitrate the current tension between local and high-z measurements of H 0.
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Keeley, Ryan E., Arman Shafieloo, Benjamin L’Huillier i Eric V. Linder. "Debiasing cosmic gravitational wave sirens". Monthly Notices of the Royal Astronomical Society 491, nr 3 (28.11.2019): 3983–89. http://dx.doi.org/10.1093/mnras/stz3304.
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ABSTRACT Accurate estimation of the Hubble constant, and other cosmological parameters, from distances measured by cosmic gravitational wave sirens requires sufficient allowance for the dark energy evolution. We demonstrate how model-independent statistical methods, specifically Gaussian process regression, can remove bias in the reconstruction of H(z), and can be combined to model independently with supernova distances. This allows stringent tests of both H0 and Λ cold dark matter, and can detect unrecognized systematics. We also quantify the redshift systematic control necessary for the use of dark sirens, showing that it must approach spectroscopic precision to avoid significant bias.
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Yang, Tao, Rong-Gen Cai i Hyung Mok Lee. "Space-borne atom interferometric gravitational wave detections. Part III. Eccentricity on dark sirens". Journal of Cosmology and Astroparticle Physics 2022, nr 10 (1.10.2022): 061. http://dx.doi.org/10.1088/1475-7516/2022/10/061.
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Abstract Eccentricity of the inspiraling compact binaries can greatly improve the distance inference and source localization of dark sirens. In this paper, we continue the research for the space-borne atom interferometric gravitational-wave detector AEDGE and investigate the effects of eccentricity on the dark sirens observed by AEDGE in the mid-band. We simulate five types of typical compact binaries with component mass ranging from 1-100 M ⊙. The largest improvement for both distance inference and localization can be as much as 1.5–3 orders of magnitude. We then construct the catalogs of dark sirens observed by AEDGE in five years. We find eccentricity is crucial to the detection of golden binary black holes (BBH) whose host galaxy can be uniquely identified. With only 5–10 golden dark BBHs one can obtain a 2 percent precision measurement of H 0 which is sufficient to arbitrate the Hubble tension. Regardless of eccentricity, AEDGE can also observe tens of golden binary neutron stars (BNS) and neutron star-black hole binaries (NSBH) with unique host galaxies. These golden dark sirens can serve as early warnings for the follow-up observations of gravitational waves in the high frequency band as well as the search of their electromagnetic counterparts. Our results show eccentricity is a crucial factor in the detection, data analysis, and application of GWs with the atom interferometers in the mid-band.
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Yu, Jiming, Zhengyan Liu, Xiaohu Yang, Yu Wang, Pengjie Zhang, Xin Zhang i Wen Zhao. "Measuring the Hubble Constant of Binary Neutron Star and Neutron Star–Black Hole Coalescences: Bright Sirens and Dark Sirens". Astrophysical Journal Supplement Series 270, nr 2 (22.01.2024): 24. http://dx.doi.org/10.3847/1538-4365/ad0ece.
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Abstract Observations of gravitational waves (GW) provide us with a new probe to study the Universe. GW events can be used as standard sirens if their redshifts are measured. Normally, standard sirens can be divided into bright/dark sirens according to whether the redshifts are measured by electromagnetic (EM) counterpart observations. First, we investigate the capability of the 2.5 m Wide-Field Survey Telescope (WFST) to take follow-up observations of kilonova counterparts. For binary neutron star (BNS) bright sirens, WFST is expected to observe 10–20 kilonovae per year in the second-generation GW detection era. As for neutron star–black hole (NSBH) mergers, when a BH spin is extremely high and the neutron star (NS) is stiff, the observation rate is ∼10 per year. Combining optical and GW observations, the bright sirens are expected to constrain the Hubble constant H 0 to ∼2.8% in five years of observations. As for dark sirens, the tidal effects of NSs during merging provide us with a cosmological model-independent approach to measure the redshifts of GW sources. Then we investigate the applications of tidal effects in redshift measurements. We find in the third generation era, the host galaxy groups of around 45% BNS mergers at z < 0.1 can be identified through this method, if the equation of state is ms1, which is roughly equivalent to the results from luminosity distant constraints. Therefore, tidal effect observations provide a reliable and cosmological model-independent method of identifying BNS mergers’ host galaxy groups. Using this method, the BNS/NSBH dark sirens can constrain H 0 to 0.2%/0.3% over a five-year observation period.
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Borhanian, Ssohrab, Arnab Dhani, Anuradha Gupta, K. G. Arun i B. S. Sathyaprakash. "Dark Sirens to Resolve the Hubble–Lemaître Tension". Astrophysical Journal 905, nr 2 (21.12.2020): L28. http://dx.doi.org/10.3847/2041-8213/abcaf5.
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Gair, Jonathan R., Archisman Ghosh, Rachel Gray, Daniel E. Holz, Simone Mastrogiovanni, Suvodip Mukherjee, Antonella Palmese i in. "The Hitchhiker’s Guide to the Galaxy Catalog Approach for Dark Siren Gravitational-wave Cosmology". Astronomical Journal 166, nr 1 (22.06.2023): 22. http://dx.doi.org/10.3847/1538-3881/acca78.
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Abstract We outline the “dark siren” galaxy catalog method for cosmological inference using gravitational wave (GW) standard sirens, clarifying some common misconceptions in the implementation of this method. When a confident transient electromagnetic counterpart to a GW event is unavailable, the identification of a unique host galaxy is in general challenging. Instead, as originally proposed by Schutz, one can consult a galaxy catalog and implement a dark siren statistical approach incorporating all potential host galaxies within the localization volume. Trott & Huterer recently claimed that this approach results in a biased estimate of the Hubble constant, H 0, when implemented on mock data, even if optimistic assumptions are made. We demonstrate explicitly that, as previously shown by multiple independent groups, the dark siren statistical method leads to an unbiased posterior when the method is applied to the data correctly. We highlight common sources of error possible to make in the generation of mock data and implementation of the statistical framework, including the mismodeling of selection effects and inconsistent implementations of the Bayesian framework, which can lead to a spurious bias.
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Chen, Anson, Rachel Gray i Tessa Baker. "Testing the nature of gravitational wave propagation using dark sirens and galaxy catalogues". Journal of Cosmology and Astroparticle Physics 2024, nr 02 (1.02.2024): 035. http://dx.doi.org/10.1088/1475-7516/2024/02/035.
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Abstract The dark sirens method enables us to use gravitational wave events without electromagnetic counterparts as tools for cosmology and tests of gravity. Furthermore, the dark sirens analysis code gwcosmo can now robustly account for information coming from both galaxy catalogues and the compact object mass distribution. We present here an extension of the gwcosmo code and methodology to constrain parameterized deviations from General Relativity that affect the propagation of gravitational waves under the ΛCDM expansion history of the universe. We show results of our analysis using data from the GWTC-3 gravitational wave catalogues, in preparation for application to the O4 observing run. After testing our pipelines using the First Two Years mock data set, we reanalyse 46 events from GWTC-3, and combine the posterior for BBH and NSBH sampling results for the first time. We obtain joint constraints on H 0 and parameterized deviations from General Relativity in the Power Law + Peak BBH population model. With increased galaxy catalogue support in the future, our work sets the stage for dark sirens to become a powerful tool for testing gravity.
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Cai, Rong-Gen, i Tao Yang. "Space-borne atom interferometric gravitational wave detections. Part I. The forecast of bright sirens on cosmology". Journal of Cosmology and Astroparticle Physics 2021, nr 12 (1.12.2021): 017. http://dx.doi.org/10.1088/1475-7516/2021/12/017.
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Abstract Atom interferometers (AIs) as gravitational-wave (GW) detectors have been proposed a decade ago. Both ground and space-based projects will be in construction and preparation in the near future. In this paper, for the first time, we investigate the potential of the space-borne AIs on detecting GW standard sirens and hence the applications on cosmology. We consider AEDGE as our fiducial AI GW detector and estimate the number of bright sirens that would be obtained within a 5-years data-taking period of GW and with the follow-up observation of electromagnetic (EM) counterparts. We then construct the mock catalogue of bright sirens and predict their ability on constraining cosmological parameters such as the Hubble constant, dynamics of dark energy, and modified gravity theory. Our preliminary results show around order 𝒪 (30) bright sirens can be obtained from a 5-years operation time of AEDGE and the follow-up observation of EM counterparts. The bright sirens alone can measure H 0 with a precision 2.1%, which is sufficient to arbitrate the Hubble tension. Combining current most precise electromagnetic experiments, the inclusion of AEDGE bright sirens can improve the measurement of the equation of state of dark energy, though marginally. Moreover, by modifying GW propagation on cosmological scales, the deviations from general relativity (modified gravity theory effects) can be constrained at 5.7% precision level.
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Chen, Ju, Changshuo Yan, Youjun Lu, Yuetong Zhao i Junqiang Ge. "On Dark Gravitational Wave Standard Sirens as Cosmological Inference and Forecasting the Constraint on Hubble Constant using Binary Black Holes Detected by Deci-hertz Observatory". Research in Astronomy and Astrophysics 22, nr 1 (1.01.2022): 015020. http://dx.doi.org/10.1088/1674-4527/ac3992.
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Abstract Gravitational wave (GW) signals from compact binary coalescences can be used as standard sirens to constrain cosmological parameters if their redshift can be measured independently by electromagnetic signals. However, mergers of stellar binary black holes (BBHs) may not have electromagnetic counterparts and thus have no direct redshift measurements. These dark sirens may be still used to statistically constrain cosmological parameters by combining their GW measured luminosity distances and localization with deep redshift surveys of galaxies around it. We investigate this dark siren method to constrain cosmological parameters in detail by using mock BBH and galaxy samples. We find that the Hubble constant can be constrained well with an accuracy ≲1% with a few tens or more of BBH mergers at redshift up to 1 if GW observations can provide accurate estimates of their luminosity distance (with relative error of ≲0.01) and localization (≲0.1 deg2), though the constraint may be significantly biased if the luminosity distance and localization errors are larger. We also introduce a simple method to correct this bias and find it is valid when the luminosity distance and localization errors are modestly large. We further generate mock BBH samples, according to current constraints on BBH merger rate and the distributions of BBH properties, and find that the Deci-hertz Observatory (DO) in a half year observation period may detect about one hundred BBHs with signal-to-noise ratio ϱ ≳ 30, relative luminosity distance error ≲0.02 and localization error ≲0.01 deg2. By applying the dark standard siren method, we find that the Hubble constant can be constrained to the ∼0.1%–1% level using these DO BBHs, an accuracy comparable to the constraints obtained by using electromagnetic observations in the near future, thus it may provide insight into the Hubble tension. We also demonstrate that the constraint on the Hubble constant applying this dark siren method is robust and does not depend on the choice of the prior for the properties of BBH host galaxies.
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Linder, Eric V. "Gravitational wave sirens as a triple probe of dark energy". Journal of Cosmology and Astroparticle Physics 2008, nr 03 (20.03.2008): 019. http://dx.doi.org/10.1088/1475-7516/2008/03/019.
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Escamilla-Rivera, Celia, i Antonio Nájera. "Dynamical dark energy models in the light of gravitational-wave transient catalogues". Journal of Cosmology and Astroparticle Physics 2022, nr 03 (1.03.2022): 060. http://dx.doi.org/10.1088/1475-7516/2022/03/060.
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Abstract The study of current gravitational waves (GW) catalogues provide an interesting model independent way to understand further the nature of dark energy. In this work, we present an update of the constrains related to dynamical dark energy parametrisations using recent Gravitational-Wave Transient catalogues (GWTC-1 and GWTC-2) along with Type Ia supernova (SNeIa) and Cosmic Chronometers (CC) catalogues. According to our Bayesian results using the full SNeIa+CC+GW database, the ΛCDM model shows a strong preference against two dark energy parameterisation known as Barboza-Alcaniz (BA) and the Low Correlation (LC) models. Also, we obtain a very strong preference against the Chevallier-Polarski-Linder (CPL) model. Furthermore, we generated a mock GW catalogue and estimate that we require approximately 1000 standard sirens to have a constrain of H 0 within 1% relative error, quantity that is out of reach of current standard sirens candidates in GWTC-1 and GWTC-2 catalogues.
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Bonilla, Alexander, Suresh Kumar, Rafael C. Nunes i Supriya Pan. "Reconstruction of the dark sectors’ interaction: A model-independent inference and forecast from GW standard sirens". Monthly Notices of the Royal Astronomical Society 512, nr 3 (12.03.2022): 4231–38. http://dx.doi.org/10.1093/mnras/stac687.
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ABSTRACT Interacting dark matter (DM) – dark energy (DE) models have been intensively investigated in the literature for their ability to fit various data sets as well as to explain some observational tensions persisting within the ΛCDM cosmology. In this work, we employ the Gaussian processes (GP) algorithm to perform a joint analysis by using the geometrical cosmological probes such as Cosmic chronometers, Supernova Type Ia, Baryon Acoustic Oscillations, and the H0LiCOW lenses sample to infer a reconstruction of the coupling function between the dark components in a general framework, where the DE can assume a dynamical character via its equation of state. In addition to the joint analysis with these data, we simulate a catalogue with standard siren events from binary neutron star mergers, within the sensitivity predicted by the Einstein Telescope, to reconstruct the dark sector coupling with more accuracy in a robust way. We find that the particular case, where w = −1 is fixed on the DE nature, has a statistical preference for an interaction in the dark sector at late times. In the general case, where w(z) is analysed, we find no evidence for such dark coupling, and the predictions are compatible with the ΛCDM paradigm. When the mock events of the standard sirens are considered to improve the kernel in GP predictions, we find a preference for an interaction in the dark sector at late times.
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Raffai, Peter, Mária Pálfi, Gergely Dálya i Rachel Gray. "Constraints on Coasting Cosmological Models from Gravitational-wave Standard Sirens". Astrophysical Journal 961, nr 1 (1.01.2024): 17. http://dx.doi.org/10.3847/1538-4357/ad1035.
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Abstract We present the first test of coasting cosmological models with gravitational-wave (GW) standard sirens observed in the first three observing runs of the LIGO–Virgo–KAGRA detector network. We apply the statistical galaxy catalog method adapted to coasting cosmologies and infer constraints on the H 0 Hubble constant for the three fixed values of the curvature parameter k = − 1 , 0 , + 1 in H 0 2 c − 2 units. The maximum posteriors and 68.3% highest density intervals we obtained from a combined analysis of 46 dark siren detections and a single bright siren detection are H 0 = 68.1 − 5.6 + 8.5 , 67.5 − 5.2 + 8.3 , 67.1 − 5.8 + 6.6 km s − 1 Mpc − 1 , respectively. All our constraints on H 0 are consistent within 1σ with the H 0 measured with the differential age method, which provides a constraint on H 0 in coasting cosmologies independently from k. Our results constrain all cosmological models with a(t) ∝ t linear expansion in the luminosity distance and redshift range of the 47 LIGO–Virgo detections, i.e., d L ≲ 5Gpc and z ≲ 0.8, which practically include all (both strictly linear and quasi-linear) models in the coasting model family. As we have found, the coasting models and the Lambda cold dark matter (or ΛCDM) model fit equally well to the applied set of GW detections.
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Bachega, Riis R. A., André A. Costa, E. Abdalla i K. S. F. Fornazier. "Forecasting the interaction in dark matter-dark energy models with standard sirens from the Einstein telescope". Journal of Cosmology and Astroparticle Physics 2020, nr 05 (11.05.2020): 021. http://dx.doi.org/10.1088/1475-7516/2020/05/021.
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Gray, R., C. Messenger i J. Veitch. "A pixelated approach to galaxy catalogue incompleteness: improving the dark siren measurement of the Hubble constant". Monthly Notices of the Royal Astronomical Society 512, nr 1 (11.02.2022): 1127–40. http://dx.doi.org/10.1093/mnras/stac366.
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ABSTRACT The use of gravitational wave standard sirens for cosmological analyses is becoming well known, with particular interest in measuring the Hubble constant, H0, and in shedding light on the current tension between early- and late-time measurements. The current tension is over 4σ and standard sirens will be able to provide a completely independent measurement. Dark sirens (binary black hole or neutron star mergers with no electromagnetic counterparts) can be informative if the missing redshift information is provided through the use of galaxy catalogues to identify potential host galaxies of the merger. However, galaxy catalogue incompleteness affects this analysis, and accurate modelling of it is essential for obtaining an unbiased measurement of H0. Previously most methods have assumed uniform completeness within the sky area of a gravitational wave event. This paper presents an updated methodology in which the completeness of the galaxy catalogue is estimated in a directionally dependent matter, by pixelating the sky and computing the completeness of the galaxy catalogue along each line of sight. The H0 inference for a single event is carried out on a pixel-by-pixel basis, and the pixels are combined for the final result. A reanalysis of the events in the first gravitational wave transient catalogue leads to an improvement on the measured value of H0 of approximately 5 per cent compared to the 68.3 per cent highest density interval of the equivalent LIGO and Virgo result, with H0 = $68.8^{+15.9}_{-7.8}$ km s−1 Mpc−1.
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Yu, Hang, Brian Seymour, Yijun Wang i Yanbei Chen. "Uncertainty and Bias of Cosmology and Astrophysical Population Model from Statistical Dark Sirens". Astrophysical Journal 941, nr 2 (1.12.2022): 174. http://dx.doi.org/10.3847/1538-4357/ac9da0.
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Abstract Gravitational-wave (GW) radiation from a coalescing compact binary is a standard siren, as the luminosity distance of each event can be directly measured from the amplitude of the signal. One possibility to constrain cosmology using the GW siren is to perform statistical inference on a population of binary black hole (BBH) events. In essence, this statistical method can be viewed as follows. We can modify the shape of the distribution of observed BBH events by changing the cosmological parameters until it eventually matches the distribution constructed from an astrophysical population model, thereby allowing us to determine the cosmological parameters. In this work, we derive the Cramér–Rao bound for both cosmological parameters and those governing the astrophysical population model from this statistical dark siren method by examining the Fisher information contained in the event distribution. Our study provides analytical insights and enables fast yet accurate estimations of the statistical accuracy of dark siren cosmology. Furthermore, we consider the bias in cosmology due to unmodeled substructures in the merger rate and mass distribution. We find that a 1% deviation in the astrophysical model can lead to a more than 1% error in the Hubble constant. This could limit the accuracy of dark siren cosmology when there are more than 104 BBH events detected.
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Finke, Andreas, Stefano Foffa, Francesco Iacovelli, Michele Maggiore i Michele Mancarella. "Cosmology with LIGO/Virgo dark sirens: Hubble parameter and modified gravitational wave propagation". Journal of Cosmology and Astroparticle Physics 2021, nr 08 (1.08.2021): 026. http://dx.doi.org/10.1088/1475-7516/2021/08/026.
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Yang, Weiqiang, Sunny Vagnozzi, Eleonora Di Valentino, Rafael C. Nunes, Supriya Pan i David F. Mota. "Listening to the sound of dark sector interactions with gravitational wave standard sirens". Journal of Cosmology and Astroparticle Physics 2019, nr 07 (23.07.2019): 037. http://dx.doi.org/10.1088/1475-7516/2019/07/037.
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Gray, Rachel, Freija Beirnaert, Christos Karathanasis, Benoît Revenu, Cezary Turski, Anson Chen, Tessa Baker i in. "Joint cosmological and gravitational-wave population inference using dark sirens and galaxy catalogues". Journal of Cosmology and Astroparticle Physics 2023, nr 12 (1.12.2023): 023. http://dx.doi.org/10.1088/1475-7516/2023/12/023.
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Abstract In the absence of numerous gravitational-wave detections with confirmed electromagnetic counterparts, the “dark siren” method has emerged as a leading technique of gravitational-wave cosmology. The method allows redshift information of such events to be inferred statistically from a catalogue of potential host galaxies. Due to selection effects, dark siren analyses necessarily depend on the mass distribution of compact objects and the evolution of their merger rate with redshift. Informative priors on these quantities will impact the inferred posterior constraints on the Hubble constant (H 0). It is thus crucial to vary these unknown distributions during an H 0 inference. This was not possible in earlier analyses due to the high computational cost, restricting them to either excluding galaxy catalogue information, or fixing the gravitational-wave population mass distribution and risking introducing bias to the H 0 measurement. This paper introduces a significantly enhanced version of the Python package gwcosmo, which allows joint estimation of cosmological and compact binary population parameters. This thereby ensures the analysis is now robust to a major source of potential bias. The gravitational-wave events from the Third Gravitational-Wave Transient Catalogue are reanalysed with the GLADE+ galaxy catalogue, and an updated, more reliable measurement of H 0 = 69+12 -7 km s-1 Mpc-1 is found (maximum a posteriori probability and 68% highest density interval). This improved method will enable cosmological analyses with future gravitational-wave detections to make full use of the information available (both from galaxy catalogues and the compact binary population itself), leading to promising new independent bounds on the Hubble constant.
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Asghari, Mahnaz, Alireza Allahyari i David F. Mota. "Gravitational wave probes of Barrow cosmology with LISA standard sirens". Journal of Cosmology and Astroparticle Physics 2024, nr 06 (1.06.2024): 044. http://dx.doi.org/10.1088/1475-7516/2024/06/044.
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Abstract We study the Barrow cosmological model, which proposes that quantum gravity effects create a complex, fractal structure for the universe's apparent horizon. We leverage the thermodynamics-gravity conjecture. By applying the Clausius relation to the apparent horizon of the Friedmann-Lemaître-Robertson-Walker universe within this framework, we derive modified field equations where the Barrow entropy is linked to the horizon. We assess the Barrow cosmology against current observations — cosmic microwave background, supernovae, and baryon acoustic oscillations data — and include projections for future Laser Interferometer Space Antenna (LISA) standard sirens (SS). Our numerical results suggest a modest improvement in the Hubble tension for Barrow cosmology with phantom dark energy behavior, compared to the standard cosmological model. Furthermore, incorporating simulated LISA SS data alongside existing observational constraints tightens the limitations on cosmological parameters, particularly the deformation exponent.
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Yang, Weiqiang, Supriya Pan, David F. Mota i Minghui Du. "Forecast constraints on anisotropic stress in dark energy using gravitational waves". Monthly Notices of the Royal Astronomical Society 497, nr 1 (2.07.2020): 879–93. http://dx.doi.org/10.1093/mnras/staa1859.
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ABSTRACT It is always interesting to investigate how well can a future experiment perform with respect to others (present or future ones). Cosmology is really an exciting field where a lot of puzzles are still unknown. In this paper, we consider a generalized dark energy (DE) scenario where anisotropic stress is present. We constrain this generalized cosmic scenario with an aim to investigate how gravitational waves standard sirens (GWSS) may constrain the anisotropic stress, which, according to the standard cosmological probes, remains unconstrained. In order to do this, we generate the luminosity distance measurements from $\mathcal {O} (10^3)$ mock GW events that match the expected sensitivity of the Einstein Telescope. Our analyses report that, first of all, GWSS can give better constraints on various cosmological parameters compared to the usual cosmological probes, but the viscous sound speed appearing due to the DE anisotropic stress is totally unconstrained even after the inclusion of GWSS.
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Leyde, K., S. Mastrogiovanni, D. A. Steer, E. Chassande-Mottin i C. Karathanasis. "Current and future constraints on cosmology and modified gravitational wave friction from binary black holes". Journal of Cosmology and Astroparticle Physics 2022, nr 09 (1.09.2022): 012. http://dx.doi.org/10.1088/1475-7516/2022/09/012.
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Abstract Gravitational wave (GW) standard sirens are well-established probes with which one can measure cosmological parameters, and are complementary to other probes like the cosmic microwave background (CMB) or supernovae standard candles. Here we focus on dark GW sirens, specifically binary black holes (BBHs) for which there is only GW data. Our approach relies on the assumption of a source frame mass model for the BBH distribution, and we consider four models that are representative of the BBH population observed so far. In addition to inferring cosmological and mass model parameters, we use dark sirens to test modified gravity theories. These theories often predict different GW propagation equations on cosmological scales, leading to a different GW luminosity distance which in some cases can be parametrized by variables Ξ0 and n. General relativity (GR) corresponds to Ξ0 = 1. We perform a joint estimate of the population parameters governing mass, redshift, the variables characterizing the cosmology, and the modified GW luminosity distance. We use data from the third LIGO-Virgo-KAGRA observation run (O3) and find — for the four mass models and for three signal-to-noise ratio (SNR) cuts of 10, 11, 12 — that GR is consistently the preferred model to describe all observed BBH GW signals to date. Furthermore, all modified gravity parameters have posteriors that are compatible with the values predicted by GR at the 90% confidence interval (CI). We then focus on future observation runs O4 and O5, and for simplicity consider one specific mass model. We show that there are strong correlations between cosmological, astrophysical and modified gravity parameters. If GR is the correct theory of gravity, and assuming narrow priors on the cosmological parameters, we forecast an uncertainty of the modified gravity parameter Ξ0 of 51% with ∼ 90 detections at O4-like sensitivities, and Ξ0 of 20% with an additional ∼ 400 detections at O5-like sensitivity. We also consider how these forecasts depend on the current uncertainties of BBHs population distributions.
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Caprini, Chiara, i Nicola Tamanini. "Constraining early and interacting dark energy with gravitational wave standard sirens: the potential of the eLISA mission". Journal of Cosmology and Astroparticle Physics 2016, nr 10 (5.10.2016): 006. http://dx.doi.org/10.1088/1475-7516/2016/10/006.
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Poddar, Tanmay Kumar, Anish Ghoshal i Gaetano Lambiase. "Listening to dark sirens from gravitational waves : Combined effects of fifth force, ultralight particle radiation, and eccentricity". Physics of the Dark Universe 46 (grudzień 2024): 101651. http://dx.doi.org/10.1016/j.dark.2024.101651.
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Di Valentino, Eleonora. "A combined analysis of the H0 late time direct measurements and the impact on the Dark Energy sector". Monthly Notices of the Royal Astronomical Society 502, nr 2 (22.01.2021): 2065–73. http://dx.doi.org/10.1093/mnras/stab187.
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ABSTRACT We combine 23 Hubble constant measurements based on Cepheids-SN Ia, TRGB-SN Ia, Miras-SN Ia, Masers, Tully Fisher, Surface Brightness Fluctuations, SN II, Time-delay Lensing, Standard Sirens and γ-ray Attenuation, obtaining our best optimistic H0 estimate, that is H0 = 72.94 ± 0.75 km s–1 Mpc–1 at 68 per cent CL. This is in 5.9σ tension with the ΛCDM model, therefore we evaluate its impact on the extended Dark Energy cosmological models that can alleviate the tension. We find more than 4.9σ evidence for a phantom Dark Energy equation of state in the wCDM scenario, the cosmological constant ruled out at more than 3σ in a w0waCDM model and more than 5.7σ evidence for a coupling between Dark Matter and Dark Energy in the IDE scenario. Finally, we check the robustness of our results; and we quote two additional combinations of the Hubble constant. The ultra-conservative estimate, H0 = 72.7 ± 1.1 km s–1 Mpc–1 at 68 per cent CL, is obtained removing the Cepheids-SN Ia and the Time-Delay Lensing based measurements, and confirms the evidence for new physics.
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Naem, Dr Ali Dakhil Naem. "ARAB MUSLIM CHARACTERS IN KHADRA’S NOVEL THE SIRENS OF BAGHDAD". Thi Qar Arts Journal 1, nr 44 (31.12.2023): 1–22. http://dx.doi.org/10.32792/tqartj.v1i44.466.
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In this study, the researcher presented the American’s views of Islam and Muslims in Khadra’s Novel The Sirens of Baghdad. The image of Arab Muslim character is portrayed differently by the post-colonial novelists post September attacks 2001 on the World Trade Centre towers situated in New York City, USA. Since the accident, many American writers who represent the Western values have endeavored to stigmatize the picture of Arab Muslims through their writings using variant depictions to confirm their ‘Others’ as they consider the Arab Muslims their foes in the world. Consequently, the American writers perpetuate their previous negative picture to continue their domination upon the Arab Muslims, using post-colonial concepts in their portrayal. In contrast, the Arab writers try their best to depict the image of the Arab Muslim characters fairly as they have realistically witnessed and experienced the actual life events. Due to this, Orientalism, stereotyping, otherness and racism are the key concepts examined in this study related the Sirens of Baghdad. As many other Western and Arab writers have dealt with the same concepts previously, the current study examined and identified the concepts differently through this study concerning Arab Muslim characters from contrasting perspectives. Accordingly, the researcher adapted Said’s Orientalism theory as a main method of analysis. The research findings revealed that the American novelists purposely reflected dark aspects of the Arab Muslim characters so as to show to the world that Islam is a religion that propagates oppression and violence. On the other hand, the Arab novelists successfully and realistically proved that it is the Westerners who most of the time oppress the Arab Muslims and murder a fairly good number of them on the basis of false and unfounded allegations. As a conclusion, the study proposes a framework of the portrayal of the Arab Muslim characters conceptualized by the post-colonial perspective. It is recommended that future research examines the reliability and authentication of the respective American novels that have distorted the Arab Muslim identity by using high level of fictitious representations that is very distant from reality and truth, so that the negative representations of the Arab Muslim characters can righteously be repudiated. Moreover, future research can explore cross-cultural studies related to the novel concerned and the like of them so as to highlight the psychological, cultural and societal representations of the two nations—the Arab and
the Western.
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Yan, Changshuo, Wen Zhao i Youjun Lu. "On Using Inspiraling Supermassive Binary Black Holes in the PTA Frequency Band as Standard Sirens to Constrain Dark Energy". Astrophysical Journal 889, nr 2 (28.01.2020): 79. http://dx.doi.org/10.3847/1538-4357/ab60a6.
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Shiralilou, Banafsheh, Geert Raaiijmakers, Bastien Duboeuf, Samaya Nissanke, Francois Foucart, Tanja Hinderer i Andrew R. Williamson. "Measuring the Hubble Constant with Dark Neutron Star–Black Hole Mergers". Astrophysical Journal 955, nr 2 (28.09.2023): 149. http://dx.doi.org/10.3847/1538-4357/acf3dc.
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Abstract Detection of gravitational waves (GWs) from neutron star-black hole (NSBH) standard sirens provides local measurements of the Hubble constant (H 0), regardless of the detection of an electromagnetic (EM) counterpart, given that matter effects can be exploited to break the redshift degeneracy of the GW waveforms. The distinctive merger morphology and the high-redshift detectability of tidally disrupted NSBH make them promising candidates for this method. Also, the detection prospects of an EM counterpart for these systems will be limited to z < 0.8 in the optical, in the era of future GW detectors. Using recent constraints on the equation of state of NSs from multi-messenger observations of NICER and LIGO/Virgo/KAGRA, we show the prospects of measuring H 0 solely from GW observation of NSBH systems, achievable by the Einstein telescope (ET) and Cosmic Explorer (CE) detectors. We first analyze individual events to quantify the effect of high-frequency (≥500 Hz) tidal distortions on the inference of NS tidal deformability parameter (Λ) and hence on H 0. We find that disruptive mergers can constrain Λ up to ( 60 % ) more precisely than nondisruptive ones. However, this precision is not sufficient to place stringent constraints on the H 0 from individual events. By performing Bayesian analysis on simulated NSBH data (up to N = 100 events, corresponding to a day of observation) in the ET+CE detectors, we find that NSBH systems enable unbiased 4%–13% precision on the estimate of H 0 (68% credible interval). This is a similar measurement precision found in studies analyzing NSBH mergers with EM counterparts in the LVKC O5 era.
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Rezaei, Mehdi, Supriya Pan, Weiqiang Yang i David F. Mota. "Evidence of dynamical dark energy in a non-flat universe: current and future observations". Journal of Cosmology and Astroparticle Physics 2024, nr 01 (1.01.2024): 052. http://dx.doi.org/10.1088/1475-7516/2024/01/052.
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Abstract We investigate the dark energy phenomenology in an extended parameter space where we allow the curvature density of our universe as a free-to-vary parameter. The inclusion of the curvature density parameter is motivated from the recently released observational evidences indicating the closed universe model at many standard deviations. Here we assume that the dark energy equation-of-state follows the PADE approximation, a generalized parametrization that may recover a variety of existing dark energy models. Considering three distinct PADE parametrizations, labeled as PADE-I, SPADE-I and PADE-II, we first constrain the cosmological scenarios driven by them using the joint analyses of a series of recently available cosmological probes, namely, Pantheon sample of Supernovae Type Ia, baryon acoustic oscillations, big bang nucleosynthesis, Hubble parameter measurements from cosmic chronometers, cosmic microwave background distance priors from Planck 2018 and then we include the future Gravitational Waves standard sirens (GWSS) data from the Einstein telescope with the combined analyses of these current cosmological probes. We find that the current cosmological probes indicate a very strong evidence of a dynamical dark energy at more than 99% C.L. in both PADE-I, and PADE-II, but no significant evidence for the non-flat universe is found in any of these parametrizations. Interestingly, when the future GWSS data from the Einstein telescope are included with the standard cosmological probes an evidence of a non-flat universe is found in all three parametrizations together with a very strong preference of a dynamical dark energy at more than 99% C.L. in both PADE-I, and PADE-II. Although from the information criteria analysis, namely, AIC, BIC, DIC, the non-flat Λ-Cold Dark Matter model remains the best choice, however, in the light of DIC, PADE parametrizations are still appealing.
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Matos, Isabela, Miguel Quartin, Luca Amendola, Martin Kunz i Riccardo Sturani. "A model-independent tripartite test of cosmic distance relations". Journal of Cosmology and Astroparticle Physics 2024, nr 08 (1.08.2024): 007. http://dx.doi.org/10.1088/1475-7516/2024/08/007.
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Abstract Cosmological distances are fundamental observables in cosmology. The luminosity (D L), angular diameter (D A) and gravitational wave (D GW) distances are all trivially related in General Relativity assuming no significant absorption of photons in the extragalactic medium, also known as cosmic opacity. Supernovae have long been the main cosmological standard candle, but bright standard sirens are now a proven alternative, with the advantage of not requiring calibration with other astrophysical sources. Moreover, they can also measure deviations from modified gravity through discrepancies between D L and D GW. However, both gravitational and cosmological parameters are degenerate in the Hubble diagram, making it hard to properly detect beyond standard model physics. Finally, recently a model-independent method named FreePower was proposed to infer angular diameter distances from large-scale structure which is independent of the knowledge of both early universe and dark energy physics. In this paper we propose a tripartite test of the ratios of these three distances with minimal amount of assumptions regarding cosmology, the early universe, cosmic opacity and modified gravity. We proceed to forecast this test with a combination of LSST and Roman supernovae, Einstein Telescope bright sirens and a joint DESI-like + Euclid-like galaxy survey. We find that even in this very model-independent approach we will be able to detect, in each of many redshift bins, percent-level deviations in these ratios of distances, allowing for very precise consistency checks of ΛCDM and standard physics. It can also result in sub-percent measurements of H 0.
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Sheldon, Elizabeth L., Carla J. Hart, Anna Wilkinson, Carl Soulsbury, Victoria F. Ratcliffe i Daniel S. Mills. "Working dogs in dynamic on-duty environments: The impact of dark adaptation, strobe lighting and acoustic distraction on task performance". PLOS ONE 19, nr 2 (8.02.2024): e0295429. http://dx.doi.org/10.1371/journal.pone.0295429.
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Sudden changes in sound and light (e.g., sirens and flashing police beacons) are a common component of working dogs’ on-duty environment. Yet, how such stimuli impact dogs’ ability to perform physical and cognitive tasks has not been explored. To address this shortcoming, we compared the accuracy and time taken for twelve dogs to complete a complex physical and cognitive task, before, during and after exposure to three ‘real-world’ stimuli: an acoustic distractor (85dB), white strobe lighting (5, 10 & 15 Hz), and exposure to a dazzling white, red, or blue lights. We found that strobe lighting, and to a greater extent, acoustic distraction, significantly reduced dogs’ physical performance. Acoustic distraction also tended to impair dogs’ cognitive performance. Dazzling lights had no effect on task performance. Most (nine out of twelve) dogs sensitised to the acoustic distraction to the extent of non-participation in the rewarded task. Our results suggest that without effective distractor response training, sudden changes in noise and flickering lights are likely to impede cognitive and physical task performance in working dogs. Repeated uncontrolled exposure may also amplify these effects.
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Liu, Yuting, Shuo Cao, Xiaogang Zheng, Marek Biesiada, Jianyong Jiang i Tonghua Liu. "Distinguishing ΛCDM from Evolving Dark Energy with Om Two-point Statistics: Implications from the Space-borne Gravitational-wave Detector". Astrophysical Journal 966, nr 1 (23.04.2024): 19. http://dx.doi.org/10.3847/1538-4357/ad3102.
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Abstract The Omh 2(z i , z j ) two-point diagnostics was proposed as a litmus test of the ΛCDM model, and measurements of the cosmic expansion rate H(z) have been extensively used to perform this test. The results obtained so far suggested a tension between observations and predictions of the ΛCDM model. However, the data set of H(z) direct measurements from cosmic chronometers and baryon acoustic oscillations was quite limited. This motivated us to study the performance of this test on a larger sample obtained in an alternative way. In this paper, we propose that gravitational-wave (GW) standard sirens could provide large samples of H(z) measurements in the redshift range of 0 < z < 5, based on the measurements of the dipole anisotropy of luminosity distance arising from the matter inhomogeneities of the large-scale structure and the local motion of the observer. We discuss the effectiveness of our method in the context of the space-borne DECi-herz Interferometer Gravitational-wave Observatory, based on a comprehensive H(z) simulated data set from binary neutron star merger systems. Our results indicate that in the GW domain, the Omh 2(z i , z j ) two-point diagnostics could effectively distinguish whether ΛCDM is the best description of our Universe. We also discuss the potential of our methodology in determining possible evidence for dark energy evolution, focusing on its performance on the constant and redshift-dependent dark energy equation of state.
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Laghi, Danny, Nicola Tamanini, Walter Del Pozzo, Alberto Sesana, Jonathan Gair, Stanislav Babak i David Izquierdo-Villalba. "Gravitational-wave cosmology with extreme mass-ratio inspirals". Monthly Notices of the Royal Astronomical Society 508, nr 3 (2.10.2021): 4512–31. http://dx.doi.org/10.1093/mnras/stab2741.
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ABSTRACT The Laser Interferometer Space Antenna (LISA) will open the mHz frequency window of the gravitational-wave (GW) landscape. Among all the new GW sources expected to emit in this frequency band, extreme mass-ratio inspirals (EMRIs) constitute a unique laboratory for astrophysics and fundamental physics. Here, we show that EMRIs can also be used to extract relevant cosmological information, complementary to both electromagnetic (EM) and other GW observations. By using the loudest EMRIs (S/N > 100) detected by LISA as dark standard sirens, statistically matching their sky localization region with mock galaxy catalogues, we find that constraints on H0 can reach ∼1.1 per cent (∼3.6 per cent) accuracy, at the 90 per cent credible level, in our best(worst)- case scenario. By considering a dynamical dark energy (DE) cosmological model, with ΛCDM parameters fixed by other observations, we further show that in our best(worst)- case scenario ∼5.9 per cent (∼12.3 per cent) relative uncertainties at the 90 per cent credible level can be obtained on w0, the DE equation of state parameter. Besides being relevant in their own right, EMRI measurements will be affected by different systematics compared to both EM and ground-based GW observations. Cross-validation with complementary cosmological measurements will therefore be of paramount importance, especially if convincing evidence of physics beyond ΛCDM emerges from future observations.
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Yu, Jiming, Yu Wang, Wen Zhao i Youjun Lu. "Hunting for the host galaxy groups of binary black holes and the application in constraining Hubble constant". Monthly Notices of the Royal Astronomical Society 498, nr 2 (18.08.2020): 1786–800. http://dx.doi.org/10.1093/mnras/staa2465.
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ABSTRACT The discovery of gravitational-wave (GW) signals, produced by the coalescence of stellar-mass binary black holes (SBBHs), opens a new window to study the astrophysical origins and dynamical evolutions of compact binaries. In addition, these GW events can be treated as the standard sirens to constrain various cosmological parameters. Both issues require the host identification for these GW events, with help of the spatial resolution of GW detector networks. In this paper, we investigate the capabilities of various detector networks for identifying the SBBHs’ host galaxy groups, rather than their host galaxies, which can overcome the influence of galaxies’ proper motions in dark matter haloes for measuring the cosmological parameters. In our analysis, the group catalogue of SDSS DR7 with redshift z ∈ (0.01, 0.1) is considered as an example of the application. We find that for the second-generation (2G) detector network, the host galaxy groups of around (0.7–6.9) SBBHs can be identified per year assuming all sources are $30\!-\!30\, \mathrm{M}_{\odot }$ binaries, and that all five detectors in the network are in lock 100 per cent of the time. For the 3G detector network, this number becomes (3.9–40.0) yr−1. We also investigate the potential constraint on the Hubble constant H0 by these GW events, if their redshift information is extracted from the candidates of host galaxy groups. We find that, by 5-yr full time observations, 2G detector network is expected to give a constraint of $\Delta H_0/H_0\sim (1{{\ \rm per\ cent}},\ 4{{\ \rm per\ cent}})$, which can be more than two order smaller if considering the 3G detector network.
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Antinozzi, Giovanni, Matteo Martinelli i Roberto Maoli. "Forecast cosmological constraints from the number counts of Gravitational Waves events". Journal of Cosmology and Astroparticle Physics 2024, nr 05 (1.05.2024): 017. http://dx.doi.org/10.1088/1475-7516/2024/05/017.
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Abstract We present a forecast for the upcoming Einstein Telescope (ET) interferometer with two new methods to infer cosmological parameters. We consider the emission of Gravitational Waves (GWs) from compact binary coalescences, whose electromagnetic counterpart is missing, namely Dark Sirens events. Most of the methods used to infer cosmological information from GW observations rely on the availability of a redshift measurement, usually obtained with the help of external data, such as galaxy catalogues used to identify the most likely galaxy to host the emission of the observed GWs. Instead, our approach is based only on the GW survey itself and exploits the information on the distance of the GW rather than on its redshift. Since a large dataset spanning the whole distance interval is expected to fully represent the distribution, we applied our methods to the expected ET's far-reaching measuring capabilities. We simulate a dataset of observations with ET using the package darksirens, assuming an underlying ΛCDM cosmology, and including the possibility to choose between three possible Star Formation Rate density (SFR) models, also accounting for possible population III stars (PopIII). We test two independent statistical methods: one based on a likelihood approach on the theoretical expectation of observed events, and another applying the cut-and-count method, a simpler method to compare the observed number of events with the predicted counts. Both methods are consistent in their final results, and also show the potential to distinguish an incorrect SFR model from the data, but not the presence of a possible PopIII. Concerning the cosmological parameters, we find instead that ET observations by themselves would suffer from strong degeneracies, but have the potential to significantly contribute to parameter estimation if used in synergy with other surveys.
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Ballard, W., A. Palmese, I. Magaña Hernandez, S. BenZvi, J. Moon, A. J. Ross, G. Rossi i in. "A Dark Siren Measurement of the Hubble Constant with the LIGO/Virgo Gravitational Wave Event GW190412 and DESI Galaxies". Research Notes of the AAS 7, nr 11 (27.11.2023): 250. http://dx.doi.org/10.3847/2515-5172/ad0eda.
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Abstract We present a measurement of the Hubble Constant H 0 using the gravitational wave event GW190412, an asymmetric binary black hole merger detected by LIGO/Virgo, as a dark standard siren. This event does not have an electromagnetic counterpart, so we use the statistical standard siren method and marginalize over potential host galaxies from the Dark Energy Spectroscopic Instrument (DESI) survey. GW190412 is well-localized to 12 deg2 (90% credible interval), so it is promising for a dark siren analysis. The dark siren value for H 0 = 85.4 − 33.9 + 29.1 km s−1 Mpc−1, with a posterior shape that is consistent with redshift overdensities. When combined with the bright standard siren measurement from GW170817 we recover H 0 = 77.96 − 5.03 + 23.0 km s−1 Mpc−1, consistent with both early and late-time Universe measurements of H 0. This work represents the first standard siren analysis performed with DESI data, and includes the most complete spectroscopic sample used in a dark siren analysis to date.
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Permana, Muchamad fajar, Farrady alif Fiolana i Diah Arie W.K. "KLASIFIKASI SUARA SIRENE MENGGUNAKAN STFT (SHORT-TERM FOURIER TRANSFORM)". Jurnal Ilmiah Sistem Informasi 1, nr 3 (7.10.2022): 44–58. http://dx.doi.org/10.51903/juisi.v1i3.414.
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Sirene merupakan sebuah alat yang mampu menghasilkan bunyi yang mendengung keras, digunakan sebagai tanda bahaya dan sebagainya. Sirene dipergunakan pada kendaraan darurat seperti untuk ambulance, polisi dan pemadam kebakaran.. Selain itu sirene juga digunakan untuk alarm suatu bencana. Suara sirene pada kendaraan darurat juga memiliki bunyi yang berbeda-beda tergantung pada penggunaan dan penerapannya. Dalam penelitian ini data suara sirene diolah menggunakan algoritma STFT dan diklasifikasikan dengan menggunakan artificial neural network. Proses pengolahan data sirene menghasilkan bahwa nilai amplitude maksimal tertinggi sebesar 0,29(-11dB) pada frekuensi 800Hz milik sirene ambulance mode wail2. Sedangkan nilai amplitude maksimal terendah sebesar 0,03(-30dB) pada frekuensi 1,3KHz milik sirene kendaraan pemadam kebakaran. Proses learning data menghasilkan nilai MSE terkecil sebesar 0,0000066218 pada epoch ke 1000. Kemudian dari uji coba proses training data untuk pencocokan sirene kendaraan darurat, dihasilkan dari data yang di-training berjumlah 640 data, terdapat data sirene yang berjumlah 630 berhasil dan 10 gagal. Hasil uji coba memiliki persentase keberhasilan yang tinggi sesuai yang diharapkan yaitu sebesar 98,44%.
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Widodo, Ari, i Wahyu Sapto Aji. "Palang Pintu Kereta Api Pneumatik Otomatis Berbasis PLC Omron CP1E-NA20DR-A". Buletin Ilmiah Sarjana Teknik Elektro 1, nr 2 (10.09.2019): 82. http://dx.doi.org/10.12928/biste.v1i2.1011.
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One alternative in reducing accidents at railroad crossings without guards is automatic pneumatic railroad crossings. This tool uses PLC (Programmable Logic Controller) as a processing system. Automatic crossing railroad crossing works by using two proximity sensors that are placed on the right and left crossings with a distance far from the crossing (approximately 1 KM). The system outputs are pneumatically actuated sirens, lights and door lintels. At most this door will move up and down closing and opening the crossing. The use of pneumatics in manufacturing because pneumatics saves more space around the crossing and is safe. In testing, detection is done in 2 opposite directions. The results show the tool has been working to close and open crossings with good performance.Salah satu alternatif dalam mengurangi kecelakaan di pintu perlintasan kereta api tanpa penjaga adalah palang pintu kereta api pneumatik otomatis. Alat ini menggunakan PLC (Programmable Logic Controller) sebagai sistem pemroses. Palang pintu perlintasan kereta api otomatis bekerja dengan menggunakan dua buah sensor proximity yang di letakkan pada kanan dan kiri perlintasan dengan jarak yang jauh dari perlintasan (kurang lebih 1 KM). Keluaran sistem berupa aktifnya sirene, lampu, dan palang pintu yang digerakkan dengan pneumatik. Paling pintu ini akan bergerak naik dan turun menutup dan membuka perlintasan. Penggunaan pneumatik dalam pembuatan karena pneumatik lebih menghemat ruang sekitar perlintasan dan aman. Dalam pengujiannya, pendeteksian dilakukan dengan 2 arah yang berlawanan. Hasil menunjukkan alat telah bekerja menutup dan membuka perlintasan dengan kinerja yang baik.
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Williamson, Jennifer L. "The Siren Song of the Elderly: Florida's Nursing Homes and the Dark Side of Chapter 400". American Journal of Law & Medicine 25, nr 2-3 (1999): 423–43. http://dx.doi.org/10.1017/s0098858800010972.
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Nursing homes perform a vital function in the long-term care continuum by providing nursing care around the clock to the elderly and disabled. By entrusting these institutions with society's frailest members, the general population relies on government agencies and their regulations to ensure that the elderly receive quality care. States expect quality care, but providers often lack the financial support and regulatory guidance.Recently, the conflict between reimbursement and quality care received national attention. Vencor, the U.S.'s second largest nursing home chain, attempted to terminate its Medicaid contracts and evict all its Medicaid residents. Executives explained that the contract terminations and resident evictions were strategies to make room for higher paying private pay residents. Faced with state, and potentially federal, fines, as well as a district court injunction and public outrage over the patient dumping, the company quickly abandoned its policy and apologized.
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Černohorská, Hana, Eva Sobotková, Martina Kosťuková, Iveta Bihuncová i Ivana Oravcová. "Analysis of lines and breeds of sires in the breeding of the Czech warmblood horses based on grading their offspring in rearing facilities for testing young horses (RFT)". Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 61, nr 6 (2013): 1605–12. http://dx.doi.org/10.11118/actaun201361061605.
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The objective of the present study was to evaluate the effect of the breed of sire and line of sire on grading of the body conformation and performance of colts of warmblood horses in rearing facilities for testing young horses (RFT). The groundwork database contained data from 2001 to 2011 from nine RFT’s. The database was processed statistically using the GLM method to assess the statistical significance of the effect of the breed of the sire and line of the sire on body conformation and performance of the colts. By multiple comparisons of the individual effects using the Tukey-B method we discovered statistically significant differences in the body conformation and performance of colts of sires among the respective breeds and lines. The performance of the offspring of Dutch warmblood, Hanoverian horse and Holsteiner horse sires is better than of the offspring of sires of the Thoroughbred, Czech warmblood and Selle Francais. The conformation of the offspring by sires of the Holsteiner horse and Hanoverian horse breeds is superior to that of offspring by sires of the Selle Francais and Czech warmblood. The mechanics of movement of the offspring of the 2300 Shagya XVIII-Báb. line is inferior to the offspring of the following lines: 3100 Adeptus xx, 67 Dark Ronald, 1000 Der Lowe xx, 3250 Dwinger 3257, 4800 Ladykiller xx, Orange Peel xx – Alme Z, 1100 Przedswit VI-Rad., 4900 Rantzau xx – Cor De La Bryere, 4600 Rittersporn xx – Ramzes 4028, 60 St. Simon and 88 Teddy. The effect of the line of the sires on the body conformation of colts has not been proved.
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Soares-Santos, M., A. Palmese, W. Hartley, J. Annis, J. Garcia-Bellido, O. Lahav, Z. Doctor i in. "First Measurement of the Hubble Constant from a Dark Standard Siren using the Dark Energy Survey Galaxies and the LIGO/Virgo Binary–Black-hole Merger GW170814". Astrophysical Journal 876, nr 1 (26.04.2019): L7. http://dx.doi.org/10.3847/2041-8213/ab14f1.
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