C. Talbot

Determining the population properties of spinning black holes

There are at least two formation scenarios consistent with the first gravitational-wave observations of binary black hole mergers. In field models, black hole binaries are formed from stellar binaries that may undergo common envelope evolution. In dynamic models, black hole binaries are formed through capture events in globular clusters. Both classes of models are subject to significant theoretical uncertainties. Nonetheless, the conventional wisdom holds that the distribution of spin orientations of dynamically merging black holes is nearly isotropic while field-model black holes prefer to spin in alignment with the orbital angular momentum. We present a framework in which observations of black hole mergers can be used to measure ensemble properties of black hole spin such as the typical black hole spin misalignment. We show how to obtain constraints on population hyperparameters using minimal assumptions so that the results are not strongly dependent on the uncertain physics of formation models. These data-driven constraints will facilitate tests of theoretical models and help determine the formation history of binary black holes using information encoded in their observed spins. We demonstrate that the ensemble properties of binary detections can be used to search for and characterize the properties of two distinct populations of black hole mergers.

Measuring the Binary Black Hole Mass Spectrum with an Astrophysically Motivated Parameterization

Gravitational-wave detections have revealed a previously unknown population of stellar mass black holes with masses above

An introduction to Bayesian inference in gravitational-wave astronomy: parameter estimation, model selection, and hierarchical models

20, M_{odot}

Gravitational-wave memory: waveforms and phenomenology

. These observations provide a new way to test models of stellar evolution for massive stars. By considering the astrophysical processes likely to determine the shape of the binary black hole mass spectrum, we construct a parameterized model to capture key features that can relate gravitational-wave data to theoretical stellar astrophysics. Pulsational pair-instability supernovae are expected to cause all stars with initial mass