Cosmological forecasts from current observations of LIGO

TL;DR

This study uses simulated LIGO gravitational-wave data to forecast how future observations could improve constraints on cosmological parameters, especially the Hubble constant, and highlights the potential of combining gravitational and electromagnetic signals.

Contribution

It demonstrates that approximately 1000 gravitational-wave events are needed for LIGO to match Planck's precision in cosmological measurements and shows the potential of gravitational waves to complement electromagnetic observations.

Findings

At least 5 years of data (~1000 events) are needed for LIGO to match Planck's accuracy.

The Hubble constant from 1000 simulated events aligns more with local measurements than Planck.

Combining gravitational and electromagnetic signals offers promising insights into universe's physics.

Abstract

We use the simulated gravitational-wave data to explore the evolution of the universe in light of current observations of the Laser Interferometer Gravitational-Wave Observatory (LIGO). Taking advantage of state-of-the-art Markov Chain Monte Carlo technique to constrain the basic cosmological parameters, the Hubble constant, present matter density parameter and equation of state of dark energy, we find that LIGO needs about, at least 5-year data accumulation, namely about 1000 events, to achieve the accuracy comparable to the Planck result. We also find that, from a new information channel, the constrained value of the Hubble constant from 1000 simulated events is more consistent with the direct local observation by Riess et al. than the indirect global measurement by the Planck Collaboration at the $2\sigma$ confidence level. The combination of gravitational waves and electromagnetic signals is very prospective to reveal the underlying physics of the universe.