Also known as a "rotating uncharged blackhole" or a "Kerr blackhole". One of the four possible solutions to Einstien's field equations for general relativity. Unlike a standard blackhole, which has a single point singularity, a ring singularity is ring shaped because the blackhole is rotating. Any object that has spin and collapses into a blackhole would turn into a ring singularity.

Ring singularities are known to be of special interest because of the unusual phenomenons that occur near the singularity, that would not occur at a single point singularity. The structure of the rotating blackhole is different.

In a rotating blackhole, the outer layer is called the ergoshpere, which is shaped like a ovaloid. There are also two event horizons, the outer event horizon is taurus shaped. The outer event horizon acts like that of the event horizon found in a non-rotating blackhole. However the inner event horizon is different. Inside the inner event horizon space and time start acting normal again.

The real interesting part is about the ring singularity at the center. The edges of the ring singularity act like a singularity found in any non-rotating blackhole. However the central region inside of the ring according to physicists acts like either a portal to another universe, a wormhole, or both.

Majority if not all blackholes in the universe have a ring singularity. This is because all objects in the universe have some amount spin, including stars that collapse into a blackhole.
A ring singularity could act like a portal. Also, majority if not all blackholes in the universe have a ring singularity.
by MST3K I like August 30, 2022
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