James S. McDonnell Distinguished University Professor in Physics
Lyman Page, along with students and collaborators, measures 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, will help us understand how the universe evolved and how the observed structure, at sizes ranging from galaxies to superclusters of galaxies, was formed. From precise measurements of the CMB, one can also deduce many of the cosmological parameters and the physics 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, and the Hubble parameter to percent-level accuracy.