Dark Matter in the Universe
This colloquium is hosted by STScI and will be held as a fully virtual event.
3:00 PM - 4:00 PM
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 is 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, sterile neutrinos, primordial black holes, and light dark matter. 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.
Speaker: Katherine Freese (University of Texas, Austin)
All 2020 Fall Colloquium virtual talks are held on Wednesdays at 3:00 PM.
Please direct questions or comments to contact above. The 2020-2021 committee members are: Karoline Gilbert (STScI co-chair), Ethan Vishniac (JHU co-chair), Graeme Addison (JHU), Martha Boyer (STScI), Joshua Peek (STScI), Kevin Schlaufman (JHU), and Raymond Simons (STScI).