Joshua A. Frieman

Chair, Astronomy and Astrophysics

Joshua A. Frieman
Chair's Office
ERC 599E
Research Office
ERC 453
Chair's Office
(773) 834-0287
Research Office
(773) 702-7971


PhD, Physics, The University of Chicago, 1985

Postdoctoral Research Associate, Theory Group, SLAC National Laboratory, 1985-88

Distinguished Scientist, Fermilab

Research Fields

  • Cosmology Theory and Observation
  • Large-Scale Structure
  • Dark Energy
  • Gravitational Lensing
  • Supernovae as Cosmological Probes

Research Groups

  • Survey Science Group

Scientific Projects



Frieman's primary research is in theoretical and observational cosmology, including studies of dark energy and dark matter, large-scale structure, strong and weak gravitational lensing, supernovae, and the early universe. His group often uses machine learning techniques in the analysis of cosmic surveys, e.g., in estimating galaxy photometric redshifts and in the modeling of strong gravitational lens systems. He was a co-founder and later Director of the Dark Energy Survey (DES), 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 the Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile. DES 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 spectroscopically confirmed type Ia supernovae and led to improved constraints on dark energy. Frieman was a member of the Theoretical Astrophysics group and later Head of the Particle Physics Division at Fermilab, which has close connections with the cosmologists and astrophysicists at Chicago.

Frieman is an elected member of the National Academy of Sciences and a Fellow of the American Academy of Arts and Sciences, the American Association for the Advancement of Science, the American Astronomical Society, and the American Physical Society, and an Honorary Fellow of the Royal Astronomical Society. His awards include the DOE Office of Science Distinguished Scientists' Fellows 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.

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