Argonne National Laboratory

Upcoming Events

New Light Species and the CMB

HEP Theoretical Physics Seminar
Chris Brust, University of Maryland and JHU
November 5, 2013 3:00PM to 4:00PM
Building 362, Room E188
The effective number of neutrino species in our universe, Neff, is capable of probing the presence of new light or massless species in our universe. I will first review relevant facts about both CMB measurements of new light species and thermodynamics in the early universe. Then, I will present the effects of many models of BSM physics containing new light species on the CMB, including models containing eV-scale sterile neutrinos compatible with anomalies in neutrino experiments, and interpret the compatibility of the parameter space of these models in terms of the recent results from the Planck satellite. I will argue that the bounds on couplings obtained from the Planck measurement of the CMB are competitive with bounds coming from other areas of physics.