Learn · CERN

Talk1 h 20 min

The Black Hole Photon Ring

Alex Lupsasca · CERN

Watch At CERN

About

What does a black hole look like? The first images of the supermassive black hole M87* display a bright ring encircling the event horizon, which appears as a dark patch in its surrounding emission. But Einstein's theory of general relativity predicts that within this image there also lies a thin "photon ring" consisting of multiple mirror images of the main emission. These images arise from photons that orbited around the black hole multiple times, probing the warped space-time geometry just outside its horizon. The photon ring carries an imprint of the strong gravity in this region and encodes fundamental properties of the black hole (including, for instance, its quasinormal mode spectrum). A measurement of this predicted (but not yet observed) ring could provide a precise test of general relativity and will be the target of a NASA mission proposed to fly within the next decade. .

0:00:00 Slide 1

0:01:28 Slide 2

0:04:33 Slide 3

0:06:30 Slide 4

0:07:48 Slide 5

0:09:17 Slide 6

0:11:38 Slide 7

0:22:51 Slide 8

0:24:26 Slide 9

0:32:05 Slide 10

0:33:15 Slide 11

The talk

  1. The Black Hole Photon Ring 2023-03-14 · 1 h 20 min · CERN's player

Credits and licence

Institution
CERN
Department
TH String Theory Seminar
Speaker
Alex Lupsasca
Year
2023
Language
English
Source
CERN
Licence
CERN, as CERN states it. CERN's terms
Attribution
© CERN. CERN provides its audiovisual media free of charge for educational and informational use, credited to CERN; this lecture is shown in CERN's own player.
Who can watch
CERN gives no rating. Invisible Network shows it to Teens profiles and older, judged from what the source says about it. How courses are placed