Josh Frieman is a Professor of Astronomy & Astrophysics and a senior member of the Kavli Institute for Cosmological Physics at the University of Chicago. He was born and raised in Princeton, NJ, earned his bachelor’s degree in physics from Stanford in 1981 and his PhD in physics from the University of Chicago in 1989. After a postdoc in the particle theory group at SLAC National Laboratory, he joined the Fermilab scientific staff in the Theoretical Astrophysics group and later served as Head of the Fermilab Particle Physics Division. In addition to the NAS, Frieman is a Fellow of the American Academy of Arts & Sciences, the American Association for the Advancement of Science, the American Astronomical Society, and the American Physical Society (APS) and an Honorary Fellow of the Royal Astronomical Society. His awards include the DOE Office of Science Distinguished Scientists’ Fellow Award, the Pappalardo Lectureship at MIT, and the Bethe Lectureship at Cornell. He served as President of the Aspen Center for Physics from 2019 to 2022.

Research Interests

Frieman's research activities span theoretical and observational cosmology, including the early universe, large-scale structure, gravitational lensing, supernovae, dark matter and dark energy. His early research included models of primordial inflation and of late-time cosmic acceleration. The co-author of over 600 publications, he was a co-founder and later Director of the Dark Energy Survey, an international collaboration of 500 scientists from 25 institutions in 7 countries that carried out a six-year survey to map the Universe using a 570-megapixel camera it built for a 4-meter telescope in Chile. The Dark Energy Survey has catalogued several hundred million galaxies and discovered several thousand supernovae, yielding state-of-the-art measurements of cosmological parameters. Frieman previously played leadership roles in the Sloan Digital Sky Survey (SDSS) and led the SDSS-II Supernova Survey, which discovered 500 intermediate-redshift type Ia supernovae and delivered world-leading dark energy constraints in combination with other data sets. His public lecture at Fermilab in 2016, "Probing the Dark Universe", for some reason has 7.5 million views on YouTube.

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Primary Section

Section 13: Physics

Secondary Section

Section 12: Astronomy