Events

Event Information:

• Tue

  02

  Nov

  2021

  Colloquium: The Black Hole Photon Ring

  4:00 pmLewis Hall 101

  Alexandru Lupsasca
  Department of Physics
  Princeton

  The Black Hole Photon Ring

  The photon ring is a narrow ring-shaped feature, predicted by General Relativity but not yet observed, that appears on images of sources near a black hole. It is caused by extreme bending of light within a few Schwarzschild radii of the event horizon and provides a direct probe of the unstable bound photon orbits of the Kerr geometry. I will review the origin and structure of the photon ring, before discussing the prospects for its future detection. I will argue that the precise shape of the observable photon ring is remarkably insensitive to the astronomical source profile and can therefore be used as a stringent test of strong-field General Relativity. A space-based interferometry experiment targeting the photon ring of M87* could test the Kerr nature of the source to the sub-sub-percent level.

   

  Join Zoom Meeting

  https://olemiss.zoom.us/j/91928227187

  Meeting ID: 919 282 27187