Forecasts on interacting dark energy with standard sirens

TL;DR

This paper evaluates how future gravitational wave standard sirens from LISA and ET can improve constraints on interacting dark energy models, especially on the Hubble constant and dark sector couplings, when combined with other cosmological data.

Contribution

It introduces a method to forecast constraints on interacting dark energy models using mock standard siren data from future GW detectors, enhancing parameter estimation accuracy.

Findings

Standard sirens improve H_0 accuracy by an order of magnitude.

Combining GW data with SNIa and BAO refines dark sector interaction parameters.

Future GW observations can shed light on the H_0 tension.

Abstract

We present the predictions with standard sirens at Gravitational Waves detectors, such as the Laser Interferometer Space Antenna (LISA) and the Einstein Telescope (ET), for interacting dark energy theories. We focus on four models characterised by couplings between the dark energy field and the dark matter fluid arising from conformal or disformal transformations of the metric, along with an exponential self-interacting potential. To this purpose we construct mock catalogues and perform a Markov Chain Monte Carlo analysis by considering ET and LISA standard sirens, and also their combination with Baryon Acoustic Oscillations (BAO) and Supernovae Ia (SNIa) data. We find that in all the four models considered, the accuracy on the $H_0$ parameter increases by one order of magnitude at 1$\sigma$ when compared to the SNIa+BAO data set, possibly shedding light in the future on the origin of the $H_0$-tension. The combination of standard sirens with SNIa+BAO allows to improve the accuracy on some coupling and exponential parameters, hinting at future prospects for constraining interactions in the dark sector.