Sixteenth Marcel Grossmann Meeting

Three Extraordinary Theorems On Black Hole Rotation

7 Jul 2021, 11:50

20m

Talk in the parallel session Theoretical and observational studies of astrophysical black holes Theoretical and Observational Studies of Astrophysical Black Holes

Speaker

Prof. Yuan K. Ha (Temple University)

Description

We reveal three new theorems on black hole rotation previously unexplored in the Hawking era. These results are based on the quasi-local energy investigation of the black hole in Kerr spacetime.

1. The Horizon Mass Theorem states that the mass at the event horizon of any
   black hole is always twice its irreducible mass. In particular, the irreducible
   mass does not contain rotational energy.
2. The External Energy Theorem asserts that the rotational energy of a Kerr
   black hole exists completely outside the horizon. There is no rotational energy
   inside the Kerr black hole.
3. The Moment of Inertia Theorem states that a black hole with an angular
   momentum and an angular velocity at the horizon has a moment of inertia. When
   the rotation stops, there is an irreducible moment of inertia which is equal to
   mass x (Schwarzschild radius)^{2}. This is recognized as the rotational
   equivalent of the rest mass of a moving body in relativity.

These surprising discoveries indicate that what is believed to be a black hole is a mechanical body with an extended structure. Singularity does not exist. A new paradigm for black holes is presented. Astrophysical black holes are likely to be massive compact objects from which light cannot escape.

References:
1. Y.K. Ha, Horizon mass theorem, Int. J. Mod. Phys. D, Vol 14, No. 12 (2005)
2219 - 2225
2. Y.K. Ha, Weighing the black holes 0f GW150914, Int. J. Mod. Phys. D, Vol. 26,
No. 12 (2017) 1743018
3. Y.K. Ha, External energy paradigm for black holes, Int. J. Mod. Phys. A, Vol.
33, No. 31 (2018) 1844025