Lunch talk on Jan. 4, 2024

Potential bias in GW cosmology and the role of galaxy and AGN surveys for GW cosmology

Speaker:Lianggui Zhu (Peking University)

Venue:SWIFAR Building 2111

Time:12:30 PM, Thursday, Jan. 4, 2024

Abstract:

Gravitational-wave (GW) detections allow observers to directly measure the luminosity distances of GW sources without the calibration of the cosmic distance ladder, and can therefore be used as standard sirens to infer the cosmic expansion. Both the currently running GW detectors and future GW detection programs list the probe of the cosmic expansion using GW standard sirens as one of their main scientific goals. However, the published GW events detected by LIGO&Virgo&KAGRA suggest that our understanding of the population properties of GW sources is not sufficiently accurate, and that the complex spatial environments where GW sources are located can bias our parameter estimations of GW sources, then cause a bias in cosmological inference. This talk will introduce the effect of the bias in the parameter estimations of GW sources on the cosmological inference, and how AGN surveys can be used to infer the formation environments of GW sources in order to help us determine the need for GW waveform modeling.

Report PPT:SWIFAR_Lianggui Zhu.pdf