The current generation of gravitational wave detectors has provided a new window into the Universe of compact binaries. In just the first few years of operation, these detectors have revealed a previously un-detected population of stellar mass black hole binaries, and allowed the measurement of their masses, spin angular momenta, and -- in the case of neutron star binaries -- tidal deformability.
While it is interesting -- especially in the early years of gravitational wave astronomy -- to measure the properties of these objects individually, the real power will lie in measuring the bulk properties of the population they come from. What is the distribution of masses for black holes and neutron stars? The distribution of their spins? Is there a single equation of state for neutron stars, and if so, what is it? How many of these binaries are there? How has this evolved over cosmic time? With the right statistical framework, and sophisticated physical modeling, all of these questions can be answered. In addition, by using astrophysical models for their progenitors (e.g., binary stellar evolution modeling, globular cluster modeling, and other, more exotic formation channels), and computing the observed distributions they predict, one can infer the relative contribution of formation channels, as well as the properties and unknown physics of the progenitor systems. Future higher-sensitivity observing runs, including the one scheduled for this year, will provide an ever growing sample size to sharpen these answers.
In this talk I will introduce the general principles behind such population modeling, and showcase work being done in this field by myself and collaborators.