COLLOQUIUM: EXPERIMENTAL TESTS OF THE NO-HAIR THEOREMS OF BLACK HOLES
by
Mauri Valtonen(Tuorla Observatory, University of Turku and Helsinki Institute of Physics)
→
Europe/Stockholm
Oskar Klein Auditorium
Oskar Klein Auditorium
Description
One of the most extreme predictions of General Relativity is the existence
of a physical singularity, a black hole. Does it really exist? It is not
enough to find a compact dark body in space, such as the over 3 million
solar mass body in the Galactic centre, but one must also demonstrate
that it satisfies the no-hair theorems of black holes (Israel, Carter,
Hawking). Thorne (1980) suggested a simple way to prove the theorems
in a binary system: determine the mass, spin and the quadrupole moment
of the suspected black hole. For a real black hole these quantities
are connected to each other in a definite way which is different from
neutron stars or other material bodies. The first test of the no-hair
theorems using the binary black hole system in OJ287 has now been carried
out. We will describe this system, the current level of the test and
possibilities of improving the error limits in future. References:
Valtonen et al. ApJ 709, 725 (2010), CeMDA 106, 235 (2010).
