# Kerr-Newman solution (GR)

1. Apr 30, 2004

### ZelmersZoetrop

I was reading Michio Kaku's book Hyperspace when I came across his statement that black holes have to have another side to be consistent. I'm curious, since Godel showed that a given energy-momentum tensor does not nessecarily produce a unique metric, why must the kerr-newman solution be the only description of a charged rotating singularity?

2. Apr 30, 2004

### Stingray

The Kerr-Newman solution is the most general stationary, vacuum (except for EM field), asymptotically flat solution. You were missing the word "stationary," which I think is very important in making the result look reasonable.