Is the Schwarzschild Metric Solution Correct?

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SUMMARY

The discussion centers on the correctness of the Schwarzschild metric solutions, specifically comparing three different formulations. The first reference presents a solution with a positive sign for the time component and negative for the spatial components, while the second and third references show variations primarily in sign conventions. The consensus indicates that the differences are likely due to conventions regarding spacelike and timelike intervals. For definitive understanding, consulting chapter 7 of Carroll's notes is recommended, as it addresses the arbitrariness of sign in these equations.

PREREQUISITES
  • Understanding of general relativity concepts
  • Familiarity with the Schwarzschild radius
  • Knowledge of metric tensors in physics
  • Basic grasp of spacetime intervals
NEXT STEPS
  • Review chapter 7 of Sean Carroll's lecture notes on general relativity
  • Study the derivation of the Schwarzschild solution in detail
  • Examine the differences between timelike and spacelike intervals in general relativity
  • Explore the implications of sign conventions in metric solutions
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Physicists, students of general relativity, and anyone interested in the mathematical foundations of black hole physics will benefit from this discussion.

Orion1
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The solution for the Schwarzschild metric is stated from reference 1 as:

ds^2=- \left(1-\frac{r_s}{r}\right) c^2 dt^2 + \left(1-\frac{r_s}{r}\right)^{-1}dr^2+r^2(d \theta^2 +\sin^2 \theta d \phi^2)

The solution for the Schwarzschild metric is stated from references 2 as:

ds^2 = \left(1 - \frac{r_s}{r} \right) c^2 dt^2 - \left(1 - \frac{r_s}{r} \right)^{-1} dr^2 - r^2 \left(d \theta^2 + \sin^2 \theta d \phi^2 \right)

The solution for the Schwarzschild metric is stated from references 3 as:
ds^2 = \left(1 - \frac{r_s}{r} \right) c^2 dt^2 - \left(1 - \frac{r_s}{r} \right)^{-1} dr^2 - r^2 \left(d \theta^2 - \sin^2 \theta d \phi^2 \right)r_s - Schwarzschild radius

There is a difference in the sign of the elements between the stated solutions.

Which is the correct solution?
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Reference:
http://en.wikipedia.org/wiki/Deriving_the_Schwarzschild_solution
http://en.wikipedia.org/wiki/Tolman-Oppenheimer-Volkoff_equation#_ref-ov_3
http://en.wikipedia.org/wiki/Schwarzschild_metric
 
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Did you check any references outside of wikipedia?

By the looks, the only difference is the sign convention: is it spacelike or timelike intervals that are represented by real lengths? For what purpose do you want one to be "correct"?
 
Orion1 said:
The solution for the Schwarzschild metric is stated from references 3 as:
ds^2 = \left(1 - \frac{r_s}{r} \right) c^2 dt^2 - \left(1 - \frac{r_s}{r} \right)^{-1} dr^2 - r^2 \left(d \theta^2 - \sin^2 \theta d \phi^2 \right)

Might want to double-check your signs on this one. The third reference looks like it gives the same as the second reference (but distributing the last parenthetical). The differences between the first two are probably just convention, as cesiumfrog said.
 
Why don't you read chapter 7 of Carroll's notes and check for yourself (for one thing, I know that the arbitrariness of the sign is mentioned)
 

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