Gravitational-wave constraints on the cosmic opacity at $z\sim 5$: forecast from space gravitational-wave antenna DECIGO

Understand

Since gravitational waves (GWs) propagate freely through a perfect fluid, coalescing compact binary systems as standard sirens allow to measure the luminosity distance directly and provide distance measurements unaffected by the cosmic opacity.

• DECi-hertz Interferometer Gravitational-wave Observatory (DECIGO) is a future Japanese space gravitational-wave antenna sensitive to frequency range between target frequencies of LISA and ground-based detectors.
• Combining the predicted future GW observations from DECIGO and three current popular astrophysical probes (HII regions, SNe Ia Pantheon sample, quasar sample) in electromagnetic (EM) domains, one would be able to probe the opacity of the Universe at different redshifts.
• In this paper, we show that the cosmic opacity parameter can be constrained to a high precision ($\Delta \epsilon\sim 10^{-2}$) out to high redshifts ($z\sim$5).