Speaker: Ken Van Tilburg (Stanford)
Title: Your Noise is My Signal: Fundamental Physics with Intensity Interferometry
Room: 3024
Host: Hsin-Chia Cheng
Abstract: The inherent noise in the intensity of light from astrophysical sources imprints correlations in photon arrival times, forming the very signal of intensity interferometry. Recent technological advances are reviving intensity interferometers as capable tools for high-precision astronomical measurements. I will propose a technique called the "expanding ejecta method" (EEM) to determine angular diameter distances to supernovae based purely on geometry, augmenting the calibration of the cosmic distance ladder or even enabling a direct inference of the cosmic expansion rate. I will also introduce a new variant of intensity interferometry --- "extended-path intensity correlation". EPIC enables ground-based differential astrometry at microarcsecond-level precision in a field of view as large as several arcseconds on sources of high surface brightness. The scientific applications of EPIC include measuring the astrometric lensing noise induced by the structure of dark matter on sub-parsec length scales (corresponding to halos with sub-stellar masses), an observable that is exquisitely sensitive to the microphysics of dark matter.
