Rate My Professor Samuel Gralla

Samuel Gralla is Professor of Physics in the Department of Physics at the University of Arizona. He serves as core faculty in the Theoretical Astrophysics Program and is affiliated with Steward Observatory. Gralla earned his Ph.D. from the University of Chicago in 2011, advised by Robert Wald. He held postdoctoral positions at the University of Maryland from 2011 to 2014 and at Harvard University from 2014 to 2015. In 2015, he joined the University of Arizona as Assistant Professor, was promoted to Associate Professor in 2021, and advanced to Full Professor in 2025. He received the George H. Davis Fellowship in 2018.

Gralla's research specializes in theoretical gravitational physics, general relativity, and relativistic astrophysics, focusing on strong gravitational and electromagnetic fields as well as the astrophysics of black holes and neutron stars. His notable contributions include rigorous derivations of gravitational and electromagnetic self-force, analytical solutions for force-free plasmas near black holes and neutron stars, novel observational signatures of high-spin black holes, photon ring structures in black hole images relevant to the Event Horizon Telescope, interpretations of gravitational wave ringdown signals, new asymptotic symmetries of general relativity, and quantum decoherence effects from rotating black holes. Key publications comprise "Black hole shadows, photon rings, and lensing rings" (Physical Review D, 2019), "Lensing by Kerr black holes" (Physical Review D, 2020), "The shape of the black hole photon ring: A precise test of strong-field general relativity" (Physical Review D, 2020), "A rigorous derivation of gravitational self-force" (Physical Review D, 2008), "Can the EHT M87 results be used to test general relativity?" (Physical Review D, 2021), and "Observational signature of high spin at the Event Horizon Telescope" (Monthly Notices of the Royal Astronomical Society, 2018). Gralla was elected Fellow of the American Physical Society by the Division of Gravitational Physics, received the Blitzer Award for Excellence in Teaching Physics and Related Sciences in 2025, and the College of Science Galileo Circle Curie Award in 2023. He has delivered public lectures, including on spacetime and gravity, and developed innovative course materials for graduate mechanics.