Gravitaional Wave Cosmology Based On Future Standard Siren Observations

The detection of GW150914 has initiated the era of gravitational wave cosmology.Gravi-tational waves from the coalescences of compact binaries provide an absolute distance measure-ment to the sources.These sources,often referred to as“standard sirens”,can act as a novel probe to the history of cosmic expansion.Due to the insufficiency of existing events,this thesis is dedicated to forecasting the cosmological implications of gravitational wave standard sirens detected by the third-generation gravitational wave detectors,such as the Einstein Telescope and Cosmic Explorer.Our investigations can provide guidance for the design of detectors and cosmological research in the future.In Chapter 2-4,we begin with a brief introduction to general relativity and cosmology,followed by the theories of gravitational wave and standard siren.In subsequent chapters,we make forecast analysis on several cosmological issues with simulated gravitational wave data.To explain the accelerating expansion of universe,an amount of dark energy models have been proposed in the literature.Future observations on gravitational waves can bring further constraints to the dark energy models.In Chapter 5,we combine the simulated gravitational wave data with current observations to constrain four dark energy models.The results indicate that the inclusion of gravitational wave data can significantly reduce the errors of parameters,and the degeneracy between parameters are relieved.The value of spatial curvature is crucial for inflation,late-time cosmic evolution,and the formation of large scale structure.The constraining ability of future standard sirens on spatial curvature remains to be established.In Chapter 6,we apply a model-independent curvature test to current cosmic chronometer data and future gravitational wave data.The resulting curvature is consistent with our hypotheses and the overall error is at the 10^-1order.The estimation of luminosity distance is prerequisite for cosmological research with grav-itational wave,which,however,suffers from the problem of degeneracy between luminosity distance and inclination angle.In Chapter 7,we address this issue by imposing the prior of in-clination,according to the property of electromagnetic counterpart.The validity of our pipeline is manifested with simulation.Besides,it is shown that adopting tighter prior and employing multiple detectors can both increase the precision of luminosity distance.