Speaker
Description
The Hubble tension is a major cosmological problem, wherein early- and late-universe measurements of the Hubble constant are significantly discrepant. This tension can be probed by developing new measures of the Universe's expansion. In recent work, we created the stochastic siren, a novel way to measure the Hubble constant using the gravitational-wave (GW) background (GWB) arising from binary black hole mergers. This method can be deployed in parallel with the spectral siren---which considers only resolved mergers---by jointly analyzing the separate datasets of the GW foreground and background. However, the distinction between the foreground and background is ultimately artificial: the GWs we can resolve are dictated by our detectors. Distinguishing between the two sources is thus technically incorrect in some scenarios and may actually pose issues in the analysis of future GW data. In this talk, I will outline a new, unified method to measure the Hubble constant that makes no distinction between the foreground and background of GWs. I will demonstrate the method applied to simulated data and share the resulting cosmological constraints.
| Other topic / keywords: | Hubble-tension |
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