riassunto2

PT2 - Gravitational lensing and shadows

Speaker

Paganini, Claudio

Coauthors

Mars, Marc; Oancea, Marius A.; Paganini, Claudio F.

Talk Title

The Fingerprints Of Black Holes - Shadows And Their Degeneracies

Abstract

First I will introduce the concept of the shadow of a black hole and what it means for the shadows of two observers to be degenerate. I will then present our results showing that no continuous degenerations exist between the shadows of observers at any point in the exterior region of any Kerr-Newman black hole spacetime of unit mass. Therefore an observer can, by measuring the black holes shadow, in principle determine the angular momentum and the charge of the black hole under observation, as well as his radial distance from the black hole and his angle of elevation above the equatorial plane. However there does exist a degeneracy with respect to the Taub-NUT parameter and hence such solutions can not be ruled out from observations of the shadow alone.

Talk view

 

Back to previous page