“What is the Universe made of?” This question is the longest outstanding problem in all of modern physics, and it is one of the most important research topics in cosmology and particle physics today. The bulk of the mass in the Universe is thought to consist of a new kind of dark matter particle, and the hunt for its discovery in on. I'll start by discussing the evidence for the existence of dark matter in galaxies, and then show how it fits into a big picture of the Universe containing 5% atoms, 25% dark matter, and 70% dark energy. Neutrinos only constitute ½% of the content of the Universe, but much can be learned about neutrino properties from cosmological data. Leading candidates for the dark matter are Weakly Interacting Massive Particles (WIMPs), axions, and sterile neutrinos. WIMPs are a generic class of particles that are electrically neutral and do not participate in strong interactions, yet have weak-scale interactions with ordinary matter. There are multiple approaches to experimental searches for WIMPS: at the Large Hadron Collider at CERN in Geneva; in underground laboratory experiments; with astrophysical searches for dark matter annihilation products, and upcoming searches with the James Webb Space Telescope for Dark Stars, early stars powered by WIMP annihilation. Current results are puzzling and the hints of detection will be tested soon. At the end of the talk I'll briefly turn to dark energy and its effect on the fate of the Universe.
 
About the Speaker:

Dr. Katherine Freese is the George E. Uhlenbeck Professor of Physics at the University of Michigan. She served as Director of Nordita, the Institute for Theoretical Physics of the Nordic countries in Stockholm from 2014-2106 and is now Guest Professor at Stockholm University. She works on a wide range of topics in theoretical cosmology and astroparticle physics. She has been working to identify the dark matter and dark energy that permeate the universe as well as to build a successful model for the early universe immediately after the Big Bang. She is author of a book The Cosmic Cocktail: Three Parts Dark Matter, published in June 2014 by Princeton University Press.

Dr. Freese has been awarded an Honorary Doctorate (honoris cause) from the University of Stockholm in September 2012. She is a Fellow of the American Physical Society. She was awarded a Simons Foundation Fellowship in Theoretical Physics in 2012. Dr. Freese has served on many advisory panels and committees. She is a member of the Scientific Advisory Committee for the Perimeter Institute for Theoretical Physics. She was a Member of the Board of the Kavli Institute for Theoretical Physics in Santa Barbara; General Member of the Board of the Aspen Center for Physics; a member of the Astronomy and Astrophysics Advisory Committee (AAAC; mandated by Congress); and the DMSAG (Dark Matter Scientific Advisory Group). She served as Member of the Executive Board and General Councillor of the American Physical Society. She was also Member of the International Advisory Board for the Oskar Klein Center for Cosmoparticle Physics in Stockholm, Sweden.