Investigating Dark Energy with Black Hole Binaries

TL;DR

This paper explores how the evolution of supermassive black hole binaries can reveal properties of dark energy through gravitational wave signatures and orbital changes, offering a novel observational approach.

Contribution

It proposes using black hole binary evolution as a new method to investigate the dark energy equation of state, linking astrophysical observations to cosmological parameters.

Findings

Dark energy affects black hole binary evolution.

Gravitational wave signatures can indicate dark energy properties.

Orbital changes in binaries may be detectable within current limits.

Abstract

The accelerated expansion of the universe is ascribed to the existence of dark energy. Black holes accretion of dark energy induces a mass change proportional to the energy density and pressure of the background dark energy fluid. The time scale during which the mass of black holes changes considerably is too long relative to the age of the universe, thus beyond detection possibilities. We propose to take advantage of the modified black hole masses for exploring the equation of state $w[z]$ of dark energy, by investigating the evolution of supermassive black hole binaries on a dark energy background. Deriving the signatures of dark energy accretion on the evolution of binaries, we find that dark energy imprints on the emitted gravitational radiation and on the changes in the orbital radius of the binary can be within detection limits for certain supermassive black hole binaries. In this talk I describe how binaries can provide a useful tool in obtaining complementary information on the nature of dark energy, based on the work done with A.Kelleher.