Holography in the Gravitational Wave Era

The revolution unleashed by the discovery of gravitational waves will gradually unfold over the coming decades. The detection of a neutron star merger by LIGO and Virgo opened a new era in multi-messenger astronomy.

Future ground-based interferometers, such as the Cosmic Explorer and the Einstein Telescope, will extend the range of detection to the entire Universe, and the frequency to millions of detections per year. Space-based missions like LISA may discover gravitational waves from phase transitions in the early Universe.

Reaping the benefits of this experimental revolution requires a theoretical understanding of quantum matter coupled to dynamical classical gravity.

The fact that the relevant physics is often out-of-equilibrium and/or strongly coupled makes this a challenging regime for conventional approaches.

The purpose of this project is to use holography, also known as gauge/string duality, to make essential contributions in this direction. I have recently pioneered and provided proof of concept that this line of research is both powerful and feasible.

In the next five years I will turn these initial investigations into a fully-fledged research program to improve our understanding of: (i) Cosmological phase transitions, in particular of bubble dynamics and baryogenesis; (ii) Neutron stars, with a focus on out-of-equilibrium physics in binary mergers; (iii) Spacetime singularities, specifically in the presence of quantum matter effects.

These three main objectives are interconnected by two horizontal lines: (i) Identification of universal observables, which hold the best potential to make contact with experiment; (ii) Communication with other fields, which is crucial for the success of an interdisciplinary proposal.