Research Interests

I work on measuring the spatial temperature variations in the cosmic microwave background (CMB). The CMB, which pervades the universe, is the thermal afterglow of the big bang. Detailed knowledge of the magnitude and pattern of the fluctuations in temperature from spot to spot on the sky, or anisotropy, help us understand how the universe evolved and how the observed structure, at sizes ranging from galaxies to super clusters of galaxies, formed. From precise measurements of the CMB, most recently done with the Wilkinson Microwave Anisotropy Probe satellite, we have been able to deduce many of the cosmological parameters and have begun to probe the quantum mechanics of the very early universe. For example we have been able to determine the geometry and age of the universe, the cosmic density of baryons, the cosmic density of dark matter, the Hubble parameter, and the scalar spectral index.

Membership Type


Election Year


Primary Section

Section 13: Physics

Secondary Section

Section 12: Astronomy