I am under the impression that the event horizon radius of a non-rotating black hole is equal to its Schwarzchild radius. Is this correct? If yes, then I have a mixed bag of questions: Is the event horizon radius always calculated using the Schwarzschild metric, no matter what model we are talking about (including O-S model etc.)? Or, are there different methods of arriving at event horizon radius via different models? Do all models (which I think of as different interpretations of GR) end up with the same radius for the event horizon, or are there possible differences in size, including possible absence of event horizons in some models? I am assuming that the central singularity does exist in all models, but am ready to stand corrected on this.