Universe Colloquium: Black hole imaging as tests of General Relativity in the Galactic Centre

by Thomas Boller (MPE)

Wednesday 28 Jan 2015, 16:30 → 17:30 Europe/Berlin

seminar room (Excellence Cluster Universe, Boltzmannstrasse 2, Garching)

Einstein's General Relativity (GR) invented 100 years ago successfully describes gravitation. An algebraic extension of GR to pseudo-complex (pc) variables has been proposed, called pseudo-complex General Relativity (pc-GR). One of the important consequences of pc-GR theory is the presence of a field with repulsive properties. This has the effect that for very large masses the gravitational collapse is stopped and something what we call a “gray star” is formed instead of a black hole. We have performed ray-tracing simulations based on the pc-GR theory and standard GR for Sgr A* for different accretion scenarios and viewing angles for the observer. The simulated pc-GR images are clearly different from GR ray-tracing images. This provides the strongest test of GR theories. In addition we have simulated Fe K line profiles for both theories. As pc-GR discs are brighter, the integrated line flux is larger in pc-GR. The line profiles are clearly different from standar d GR. This offers a second robust measurement to test pc-GR versus GR. The Universe Colloquium is followed by a social gathering with wine and cheese.