Steve Kang Hoon Choi (skc98 at cornell dot edu)

I was an NSF Astronomy and Astrophysics Postdoctoral Fellow at Cornell University (now at UC Riverside). My primary research interest is on understanding the formation and evolution of our universe through building sensitive instruments to make precise measurements and applying modern data analysis techniques to them.

On the experimental side I am developing novel instruments using MKID arrays for the CCAT-prime project. MKIDs are a promising detector technology for making future sub-mm measurements, but they have yet to be demonstrated from the best observing sites in the world such as that to be used by CCAT-prime. As a graduate student at Princeton University I worked on a different detector technology, TES arrays, for the Atacama Cosmology Telescope (ACT receiver, middle photo below). Shown above is the cosmic microwave background polarization mapped by the Atacama Cosmology Telescope. In addition, I investigated infrared blocking filters, a crucial component in mm and sub-mm telescope receivers.

I continue to analyze data from the Atacama Cosmology Telescope. Recently, the cosmological data analysis I led resulted in a new precise measurement of the age and expansion rate of our universe (covered on Gizmodo!). I’ve also worked on searching for B-modes and characterizing foreground emission for measuring B-modes. This led to a definitive measurement of the correlation of the polarized thermal dust and synchrotron radiation from the Milky Way.

Other than the universe, I like tennis, traveling (Machu Picchu, left photo below), and physics enrichment activities (Ithaca Physics Bus event, right photo below).

Publications & CV
Publication list on ADS
Google Scholar
CV (updated 11/2022)

Collaborations
CCAT-prime
Atacama Cosmology Telescope
Simons Observatory
CMB-S4