Physical Society Colloquium

The Cosmic Microwave Background and Neutrinos

Lyman Page

Department of Physics
Princeton University

The remarkably simple standard model of cosmology has passed many tests and its basic parameters have been well constrained. A new generation of measurements now uses the CMB along with other cosmic probes such as galaxy surveys to interrogate the volume of the universe between us and the surface of last scattering to push beyond the standard model. We can, for example, use the CMB to address such questions as “What is the sum of the neutrino masses?” and “How many relativistic species of particles were there in the early universe?” We review the status of observations and present what we might hope to learn in the next half decade of observations.