Our work focuses on extracting astrophysical insights from the gravitational wave signatures of compact binary mergers. We develop and apply advanced statistical and machine learning techniques, including nonparametric models, to infer the population properties of binary black holes and neutron stars. Our research explores the astrophysical origins of these systems by mapping their mass and spin distributions. Recent projects include finding evidence for the pair-instability supernova mass gap, identifying distinct subpopulations consistent with isolated binary evolution, and investigating the impact of massive star wind mass-loss rates on merger rates.
DOI: 10.48550/arXiv.2508.18083
We detail the population properties of merging compact objects using 158 mergers from the cumulative Gravitational-Wave Transient Catalog 4.0, which includes three types of binary mergers: binary neutron star, neutron star--black hole binary, and binary black hole mergers. We resolve multiple over- and under-densities in the black hole mass distribution: features persist at primary masses of 10 M_sun and 35 M_sun with a possible third feature at ~20 M_sun.
DOI: 10.21203/rs.3.rs-7535991/v1
Stellar theory predicts a forbidden range of black-hole masses between ~50--130 M_sun due to pair-instability supernovae, but evidence for such a gap in the mass distribution has proved elusive. Here, we report evidence of the pair-instability gap in LIGO--Virgo--KAGRA's fourth gravitational wave transient catalog, with a lower boundary of 45 M_sun. We interpret these findings as evidence for a subpopulation of hierarchical mergers.
DOI: 10.48550/arXiv.2507.17052
Massive stars lose a significant fraction of their mass through stellar winds at various stages of their lives. In the last decade, the theoretical predictions, simulation, and direct observation of wind mass-loss rates in massive stars have improved significantly. We explore the astrophysical implications of an updated treatment of winds in the COMPAS population synthesis code, finding that formation rates of merging binary black holes are sensitive to the mass-loss rate prescriptions.
DOI: 10.1016/B978-0-443-21439-4.00129-2
A book chapter in the Encyclopedia of Astrophysics providing a comprehensive overview of the methods and instruments used for the detection and characterization of gravitational wave signals in the advanced detector era, detailing the noise properties and sensitivities of ground-based interferometers.
DOI: 10.48550/arXiv.2304.01288
We search for subpopulations in the LVK's third gravitational wave transient catalog by incorporating discrete latent variables in the hierarchical Bayesian inference framework. By incorporating formation channel knowledge within the mass and spin correlations found in each category, we find an over density of mergers with a primary mass of ~10 M_sun, consistent with isolated binary formation.
DOI: 10.3847/1538-4357/acb5ed
We introduce the first complete nonparametric model for the astrophysical distribution of the binary black hole (BBH) population. Constructed from basis splines, we use these models to conduct the most comprehensive data-driven investigation of the BBH population to date, simultaneously fitting nonparametric models for the BBH mass ratio, spin magnitude and misalignment, and redshift distributions.
