Fundamental Physics in Gravitational Wave Signals

Tests of General Relativity and Fundamental Physics is an important part of the mission of both ground based and space-based laser interferometer gravitational wave detectors. Numerous interesting scenarios have been identified, in which new fundamental physics is imprinted on gravitational wave signals. Ideally, one wants to go beyond testing how well General Relativity fits the data (null and consistency test) and confront it directly with alternative scenarios.

Extracting new physics from gravitational wave data and potentially interpreting it is a challenging task. Identifying gravitational wave signatures of scenarios beyond general relativity, the standard model, or the standard cosmological model and producing accurate waveforms that quantify potential deviations are an essential part of this process. The need for such waveforms will become more and more acute in the future.

The central goal of our proposal is to address this challenge. We will commence a programme that will allow us to transfers our significant expertise in fundamental physics and cosmology into gravitational wave signal modelling and work towards producing waveforms that can be used by LIGO, LISA and future laser interferometers to detect or constrain new fundamental physics. In particular, we will pursue the following lines of research:

- Alternative formulations of general relativity as the means to improve efficiency of numerical simulations that produce waveforms.

- Numerical modelling of binaries and production of complete waveforms beyond General Relativity and the Standard Model.

- The imprint of non-perturbative effects (e.g. dynamical scalarization) on the inspiral and/or merger part of a waveform. - Extreme Mass Ratio Inspiral beyond general relativity

- Gravitational wave signatures from early universe processes, including phase transitions, stochastic signals, and cosmic string networks. - Gravitational wave tests of new light fields (e.g. axion) and their coupling to gravity.

- Studying the imprint of proposed explanations to the cosmological constant problem (degravitation, phase transitions, tuning) can have on neutron stars structure and the corresponding waveforms.