|
It is well known that the Kerr solution (the unique stationary black
hole solution in general relativity) has a "ring" singularity. The common wisdom
is that all you have to do to show this is calculate the "Kretschmann" scalar
(Cabcd Cabcd in this case, Cabcd the Weyl tensor).
However, this scalar allows a six-fold infinity of directions along which it need
not diverge. To show that the ring of Kerr is singular along every direction of
approach (just like the Schwarzschild singularity) it is necessary to also consider
the scalar Cabcd *Cabcd where *Cabcd
is dual to Cabcd. Whereas this scalar allows a five-fold infinity of directions
along which it need not diverge, there is no direction along which both scalars remain
finite at the ring singularity.
|