- #36

PeterDonis

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For the case you're computing, they're the same. The Kerr metric is a vacuum solution, so its Ricci tensor is zero. So you can call it the Riemann tensor or the Weyl tensor, it doesn't matter.Vick said:For the Tidal force, I think that the Weyl Tensor is a better component than the Riemann one.

If you mean the Schwarzschild formula also works for the Kerr metric, this is known to be false.Vick said:For the escape velocity, I do think that this particular formula works for all

What are you basing this on?Vick said:as it was correct for the Kerr-Newman metric

For a stationary observer, yes, this works for both the Schwarzschild and the Kerr metrics. The specific formulas are different but the method is the same.Vick said:The time dilation factor gamma is also correct after taking reciprocal of the sqrt of the ##g_{00}## metric component.

The 4-velocity for a stationary observer has only one nonzero component, ##u^t##. That, and the fact that the vector must have unit norm, should be enough for you to compute the formula for ##u^t##.Vick said:The only trouble I have is Proper acceleration from the Christoffel component. I don't know how to make the vectors for 4-velocity!