John Carlstrom

Senior Member, KICP
Subramanyan Chandrasekhar Distinguished Service Professor, Departments of Astronomy and Astrophysics; Physics; Enrico Fermi Institute; and the College

John Carlstrom
Eckhardt Research Center
Room 341
5640 South Ellis Avenue
Chicago, IL 60637
(773) 834-0269
Valerie Smith
(773) 834-1865


Ph.D., California/Berkeley, 1988


Research Areas

Research Projects

Observational cosmology using new instruments to measure the temperature and polarization anisotropy of the Cosmic Microwave Background (CMB) radiation and the Sunyaev-Zeldovich (SZ) effects. Director of the 10 meter South Pole Telescope (SPT) project, which completed the 2500 square degrees SPT-SZ survey in three bands at arc minute resolution, and the SPTpol survey of 500 square degrees in two bands to unprecedented sensitivity. We have now deployed SPT-3G with 16,260 bolometric detectors to make deep polarization maps over 2500 square degrees. In addition to increased precision on cosmological parameters and probing Inflation, the SPT data allows investigations of extensions to the standard model, such as the number and masses of the neutrinos, and the nature of dark energy. Furthermore, the high resolution of the SPT measurements allows us to detect directly the emergence and evolution of structure in the universe through the subtle, small-angular scale distortions they impart on the background, such as gravitational lensing from the mass in the universe and the scattering from ionized gas (the SZ effects).

Through a joint Chicago/Argonne superconducting detector development collaboration, the SPT group bulit the focal plane for SPT-3G, with 16,260 detectors to increase the polarization mapping speed by an order of magnitude over SPTpol. We are now working toward scaling up detector fabrication and testing for the 500,000 detector CMB-S4 project.

I am also working on the CMB-S4, the next generation CMB ground based instrument. I am co-chair of the Interim Collaboration Coordination Committee. For more information see

News & Highlights