Testing conformal gravity with the supermassive black hole in 1H0707-495

Understand

Recently, two of us have found a family of singularity-free rotating black hole solutions in Einstein's conformal gravity.

• These spacetimes are characterized by three parameters: the black hole mass $M$, the black hole spin angular momentum $J$, and a parameter $L$ that is not specified by the theory but can be expected to be proportional to the black hole mass $M$.
• The Kerr black hole solution of Einstein's gravity is recovered for $L = 0$.
• In a previous paper, we showed that X-ray data of astrophysical black holes require $L/M < 1.2$.