Detecting Gravitational Waves with Pulsar Timing Arrays

Long-term high-precision astronomical timing observations of a network of pulsars, a pulsar timing array, open a portal onto low frequency gravitational waves. In this talk I'll discuss progress on efforts to detect both a stochastic background of gravitational radiation and gravitational waves from un-modeled bursts of gravitational waves using a pulsar timing array. I'll also address prospects for stochastic backgrounds of gravitational waves from cosmological sources in the pulsar timing band.