Event



**CANCELLED** Astro Seminar: "The Twisted Universe: The Cosmic Quest to Reveal Which End is Up"

Brian Keating (UCSD)
| David Rittenhouse Laboratory, A4

The cosmic microwave background (CMB) has spectacularly advanced our understanding of the origin, composition, and evolution of our universe. Yet there is still much to glean from this, the oldest light in the universe. Powerful telescopes are plying the skies in a quest to discover new physics. This talk concentrates on measurements by cutting-edge CMB telescopes which offer a glimpse into an exhilarating, and largely unexplored branch of astrophysics: the search for unique signatures in the polarization of the CMB. In this talk I will explain how the CMB can constrain fundamental physics phenomena such as primordial magnetism and elementary particle masses.  Tantalizing bounds on parity-violating effects such as cosmic birefringence — the rotation of the polarization plane of cosmic photons — will be discussed. I will describe early attempts to measure cosmic parity violation using distant galaxies as well as state-of the-art CMB measurements made in Chile's Atacama Desert by the POLARBEAR and upcoming Simons Array experiments.