Work

Constraining scalar-tensor modified gravity with gravitational waves and large scale structure surveys

Year: 2021

Type: article

Abstract: The first multi-messenger gravitational wave event has had a transformative effect on the space of modified gravity models. In this paper we study the enhanced tests of gravity that are possible with a future set of gravitational wave standard siren events. We perform MCMC constraint forecasts for parameters in Horndeski scalar-tensor theories. In particular, we focus on the complementarity of gravitational waves with electromagnetic large-scale structure data from galaxy surveys. We find that the addition of fifty low redshift ( z ≲ 0.2) standard sirens from the advanced LIGO network offers only a modest improvement (a factor 1.1–1.3, where 1.0 is no improvement) over existing constraints from electromagnetic observations of large-scale structures. In contrast, high redshift (up to z ∼ 10) standard sirens from the future LISA satellite will improve constraints on the time evolution of the Planck mass in Horndeski theories by a factor ∼ 5. By simulating different scenarios, we find this improvement to be robust to marginalisation over unknown merger inclination angles and to variation between three plausible models for the merger source population.

Source: Journal of Cosmology and Astroparticle Physics

DOI: 10.1088/1475-7516/2021/01/068

Authors: Tessa Baker, Ian Harrison

Institutions: Queen Mary University of London, University of Manchester, University of Oxford

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: bronze

Funder: H2020 European Research Council

Award: Delivering on the Promise of Measuring Dark Energy from Cosmic Lensing