Department of Physics, Engineering Physics & Astronomy

Department of Physics, Engineering Physics & Astronomy
Department of Physics, Engineering Physics & Astronomy

MI Seminar: Dark Matter and ALMA

Neal Dalal,
Perimeter Institute

Date: Tuesday March 20th, 2018
Time: 2:30 PM
Location: STI 501

Abstract:

The Missing Satellites Problem has remained one of the key challenges to the (otherwise) wildly successful standard cosmological model, called ΛCDM.  This model predicts that galaxies like our own Milky Way should host many thousands of small satellites, an abundance vastly exceeding the number of detected satellite galaxies.  This discrepancy either represents our first evidence for non-gravitational physics in the dark sector, or alternatively, it means that most of this low-mass substructure must be dark.  Distinguishing these scenarios requires a method to detect completely dark objects, and I will describe how gravitational lensing may be used to measure the abundance of dark matter substructure around typical galaxies.  In particular I will discuss how the new ALMA observatory is revolutionizing lensing studies of dark matter, and I will present first results from our ongoing project to use ALMA to probe dark matter physics.