Colloquium Friedmann

Séminaire général de physique de l’Institut Polytechnique de Paris
Département de physique de l’École polytechnique

THE GALACTIC CENTER BLACK HOLE, THE EFFECTS OF GENERAL RELATIVITY, AND HOW TO OBSERVE THEM

Dr. Frank EISENHAUER
Max Planck Institute for Extraterrestrial Physics,
Garching - Germany

MONDAY DECEMBER 5, 2022 FROM 6PM TO 7:15PM

BECQUEREL LECTURE HALL - ÉCOLE POLYTECHNIQUE

In 1922, cosmologist Alexander Friedmann published his seminal work « Über die Krümmung des Raumes » - about the curvature of space. Starting from the cosmological principle, he derived a set of equations for the expansion of the universe in the framework of general relativity and curved spacetime. On a much smaller scale, also black holes are ruled by the laws of general relativity and curved space and time. These objects are so massive and compact that nothing - not even light - can escape their gravity. Our presentation will portrait the 40 year journey from the first indications to the overwhelming observational evidence for a black hole in the Galactic Center. Using the world’s largest telescopes and most advanced technology, astronomers can now follow the stars orbiting the black hole, precisely measure its mass, detect the stunning effects of curved spacetime, trace the motion of hot gas close to the event horizon, and image the shadow of the black hole. In our talk we will present the effects of general relativity, the spectacular observations, and the technology behind the discoveries.