Gravitational Wave Tests of General Relativity with the Parameterized Post-Einsteinian Framework

TL;DR

This paper evaluates the potential of gravitational wave observations to test general relativity using the parameterized post-Einsteinian framework, demonstrating that future detections can significantly improve bounds on deviations from Einstein's theory.

Contribution

The study applies the ppE framework to simulated gravitational wave data, assessing its effectiveness in detecting deviations from general relativity and highlighting the importance of accurate waveform models.

Findings

Parameter biases can be severe if wrong theories are assumed.

Gravitational wave observations will surpass binary pulsar bounds on deviations from GR.

The ppE framework effectively detects potential deviations in simulated data.

Abstract

Gravitational wave astronomy has tremendous potential for studying extreme astrophysical phenomena and exploring fundamental physics. The waves produced by binary black hole mergers will provide a pristine environment in which to study strong field, dynamical gravity. Extracting detailed information about these systems requires accurate theoretical models of the gravitational wave signals. If gravity is not described by General Relativity, analyses that are based on waveforms derived from Einstein's field equations could result in parameter biases and a loss of detection efficiency. A new class of "parameterized post-Einsteinian" (ppE) waveforms has been proposed to cover this eventuality. Here we apply the ppE approach to simulated data from a network of advanced ground based interferometers (aLIGO/aVirgo) and from a future spaced based interferometer (LISA). Bayesian inference and model selection are used to investigate parameter biases, and to determine the level at which departures from general relativity can be detected. We find that in some cases the parameter biases from assuming the wrong theory can be severe. We also find that gravitational wave observations will beat the existing bounds on deviations from general relativity derived from the orbital decay of binary pulsars by a large margin across a wide swath of parameter space.