Research

My research focuses on 21 cm cosmology. Our goal is to map the early universe, both before and during the Epoch or Reionization, using the 21 cm transition of neutral hydrogen. That signal will allow us to directly study the astrophysics of reionization and eventually to make precise measurements of cosmological parameters. Though a vast amount of information is potentially accessible by tomographically mapping the early universe with low frequency radio waves, that signal is dwarfed by enormous foregrounds and significant noise. My work so far has focused on developing and applying fast, yet information-theoretically optimal techniques for estimating the power spectrum of 21 cm emission, despite those contaminants, that includes a robust accounting of the errors on those measurements.

By surveying the early universe topographically with redshifted 21 cm radiation, we hope to make precise measurements of the conditions and evolution of the universe during the first billon years.

By surveying the early universe topographically with redshifted 21 cm radiation, we hope to make precise measurements of the conditions and evolution of the universe during the first billon years.

More generally, I'm interested in:

  • Next generation radio interferometers that precisely map neutral hydrogen in the universe at increasing sensitivities and resolutions.
  • Analysis tools that preserve cosmological information and make it possible to take advantage of large data sets.
  • Forecasting future arrays and optimizing them for making various cosmological measurements.
  • onnecting 21 cm cosmology with other probes to learn more about the Epoch of Reionization and the Cosmic Dark Ages.