Rapid and Flexible GW Background Characterization using Pulsar Timing Array Data*

The nanohertz-frequency gravitational wave background (GWB) may have many sources, from supermassive black hole binary inspirals to cosmic strings and cosmological phase transitions. We would like to rigorously characterize the spectral properties of this GWB by applying Bayesian model selection and parameter estimation to Pulsar Timing Array (PTA) data, allowing us to investigate when a PTA could discriminate between these sources, and constrain model parameters. However current techniques are too slow to practically conduct this research. In this talk, I will present a new method which accelerates parameter estimation and model selection of PTA data for GWB spectral characterization, and which can also be used by the broader community to test their theoretical GWB models.