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Ph.D. Candidate:  Warren Morningstar

Research Advisor:  Roger Blandford

Date: Tuesday, June 11, 2019
Time: 11:00 AM
Location: Varian 355

Title:  Revealing the Small Scale Structure of Dark Matter with Gravitational Lensing

Abstract:  The standard model for dark matter, the Cold Dark Matter model, which accurately predicts the formation and evolution of large scale structure in the universe, appears to be in disagreement with observations of structure on much smaller scales.  It is, as of yet, unclear if this is due to astrophysical processes causing a reduction in the efficiency of star formation in low mass galaxies, or due to the suppression of low mass structure formation altogether due to exciting new dark matter microphysics.  Gravitational lensing offers a unique and luminosity-independent means of distinguishing between these possibilities.  In this talk, I will present a method to measure the small scale distribution of dark matter using gravitational lensing.  Through application of this technique to ALMA observations of the gravitational lens SDP 81, we have identified a low mass perturbing object, and placed new constraints on the abundance of low mass dark matter halos.  I also present several techniques to automate the inference of the smooth distribution of matter in these objects, which allow inference to proceed 1.6 billion times faster, and which strongly reduce the need for human supervision of the modeling process.  With these techniques in hand, we are poised to extract important information about the ever elusive dark matter.

June 11, 2019 - 11:00am
Varian 355