Steven Detweiler

Steven L. Detweiler was a theoretical physicist and professor of physics at the University of Florida best known for proposing pulsar timing arrays as a means to detect gravitational waves, an idea that led to the discovery of a stochastic gravitational wave background in 2023.

Background
Detweiler received his bachelor's degree from Princeton University in 1969 and his Ph.D. from the University of Chicago in 1976 under the supervision of James R. Ipser. In 2013, he was elected to a fellowship of the American Physical Society in recognition of his many and varied contributions to gravitational physics.

Detweiler's research focused on the dynamics of stars and black holes, as well as on the production and observation of gravitational waves. In 1975 together with Subrahmanyan Chandrasekhar, Detweiler calculated the effects of fluctuations on black holes. This is important for understanding the stability of black holes, as well as the later stages of the dynamics of black hole mergers. In 1979, Detweiler proposed the idea of a pulsar timing array to measure gravitational waves with wavelengths on the scale of light-years. This built upon an earlier proposal by Mikhail Sazhin to use individual pulsars. The idea was first taken up experimentally by Foster and Backer in 1990, and today globally there are five active pulsar timing array experiments. In 2023, this idea led to the discovery of a stochastic gravitational wave background by the NANOGrav experiment and other pulsar timing array experiments.