Dynamical Formation of Black Hole Mergers

Introduction

Gravitational wave (GW) astrophysics is bound to have an exceptional future building on the success of LIGO/Virgo and propelled by the next generation of ground-based detectors, which are expected to see hundreds-of-thousands of GW sources per year. Additionally, space-borne observatories, such as LISA and DECIGO, will make multi-band GW astrophysics a reality.

Research Program Overview

This ERC research program will lead to new ideas and tools to probe, in unprecedented ways, the origin of binary black hole (BBH) mergers, with a particular focus on constraining the dynamical formation of GW sources.

Key Objectives

I will address the outstanding question of how BBHs form and merge in our Universe by providing the GW community with:

1. Public BH Scattering Database
   The first and largest public BH scattering database, with BBH merger probabilities and GW observables derived from general-relativistic few-body interactions. These interactions are thought to dominate BBH assembly in environments ranging from globular clusters to Active-Galactic-Nuclei disks. This initiative fills a major gap and will ensure consistent progress in this field.

2. Modeling BBH Formation
   A new method for modeling the formation of BBHs in dense stellar clusters throughout cosmic time. This method will be based on a new hybrid approach that evolves BBHs on top of a stellar background, which is evolved using statistical mechanics. Combined with our BH scattering database, this framework will be the fastest and most accurate way of modeling BBH mergers in stellar clusters.

3. Direct Observation of Eccentric GW Mergers
   A new way of directly observing the formation of eccentric GW mergers in three-body scatterings through GW phase-shift measurements, which are caused by tidal forces and time-delay effects from the third body. This idea opens up the possibility of probing the origin of individual BBH mergers using LIGO/Virgo and future detectors.

Search Strategy

We will be the first group to present a new search strategy for quantifying what can be learned about each individual triple system and its astrophysical environment.