Standard candles and sirens rescue $H_0$

TL;DR

Future combined observations of binary neutron star systems with electromagnetic signals and supernovae can significantly improve constraints on cosmological parameters and potentially resolve the Hubble tension, even accounting for uncertainties in neutrino masses and dark energy.

Contribution

This paper demonstrates that gravitational-wave and electromagnetic observations of neutron star systems, combined with supernova data, can effectively address the Hubble tension and constrain key cosmological parameters.

Findings

Potential to rule out new physics as the cause of Hubble tension at >5.5σ

Constraints on neutrino masses and dark energy parameters from combined observations

Demonstrates the power of multi-messenger astronomy in cosmology

Abstract

We show that future observations of binary neutron star systems with electromagnetic counterparts together with the traditional probes of low- and high-redshift Type Ia supernovae (SNe Ia) can help resolve the Hubble tension. The luminosity distance inferred from these probes and its scatter depend on the underlying cosmology. By using the gravitational lensing of light or gravitational waves emitted by, and peculiar motion of, these systems we derive constraints on the sum of neutrino masses, the equation of state of dark energy parametrized in the form $w_0 + w_a (1-a)$, along with the Hubble constant and cold dark matter density in the universe. We show that even after marginalizing over poorly constrained physical quantities, such as the sum of neutrino masses and the nature of dark energy, low-redshift gravitational-wave observations, in combination with SNe Ia, have the potential to rule out new physics as the underlying cause of the Hubble tension at $\gtrsim 5.5\sigma$.