Joshua A. Frieman

Joshua A. Frieman is a theoretical astrophysicist who lives and works in the United States. He is Associate Lab Director of the Fundamental Physics Directorate at SLAC, formerly a senior scientist at Fermilab, and a professor of astronomy and astrophysics at the University of Chicago. Frieman is known for his work studying dark energy and cosmology, and he co-founded the Dark Energy Survey experiment. He was elected a member of the National Academy of Sciences in 2022.

Education Frieman received his undergraduate degree in physics from Stanford University in 1981 and his PhD in physics from the University of Chicago in 1985. His doctoral advisor was Michael Turner and his thesis was titled Particle Creation in Inhomogeneous Spacetimes.

Career After completing his PhD, Frieman held a postdoc position at SLAC National Accelerator Laboratory's Theory Group. Afterwards, Frieman became a scientist at Fermilab in 1988. He was head of that lab's Theoretical Astrophysics Group from 1994 to 1999. During the 1990s, one of the topics he studied was cosmic inflation.

During the 2000s, Frieman led the Sloan Digital Sky Survey's (SDSS) Supernova Survey, which discovered over 500 type Ia supernovae, aiding the study of cosmic expansion. He also served as chair of the SDSS's Collaboration Council and co-chair of its Large-Scale Structure Working Group. In these roles, he led measurements of the large-scale structure of the universe and of weak gravitational lensing. Building on his work with SDSS, These observations produced a large amount of data, which the DES collaboration is still analyzing. and also became a member of the Fermilab Center for Particle Astrophysics when the lab created the center that year. Frieman became head of Fermilab's Particle Physics Division in 2018. In 2019, the United States Department of Energy named him a DOE Office of Science Distinguished Scientists Fellow "for pioneering advances in the science of dark energy and cosmic acceleration, including leading the Sloan Digital Sky Survey-II Supernova Survey, co-founding the Dark Energy Survey and service as its Director." Frieman was also elected to a three-year term as president of the Aspen Center for Physics in 2019.

Personal life Frieman is the son of Edward A. Frieman, plasma physicist and former director of the Office of Science within the United States Department of Energy.

Honors and awards

American Physical Society Fellow, 1997 American Academy of Arts and Sciences Fellow, 2016 U.S. Department of Energy Office of Science Distinguished Scientists Fellow, 2019