Understanding the Kerr Metric: Solving for Delta and Lambda functions

  • #1
Orion1
973
3


According to Wikipedia, the equation for the Kerr metric is:
[tex]c^{2} d\tau^{2} = \left( 1 - \frac{r_{s} r}{\rho^{2}} \right) c^{2} dt^{2} - \frac{\rho^{2}}{\Lambda^{2}} dr^{2} - \rho^{2} d\theta^{2} - \left( r^{2} + \alpha^{2} + \frac{r_{s} r \alpha^{2}}{\rho^{2}} \sin^{2} \theta \right) \sin^{2} \theta \ d\phi^{2} + \frac{2r_{s} r\alpha \sin^{2} \theta }{\rho^{2}} \, c \, dt \, d\phi[/tex]

However, according to four other references listed in Reference and equations listed as attachment for brevity, the 'Delta/Lambda' function is not squared within the metric?

[tex]\frac{\rho^{2}}{\Lambda^{2}}[/tex] ?

Which equation reference is the correct equation solution for the Kerr metric?
[/Color]
Reference:
http://en.wikipedia.org/wiki/Kerr_metric#Mathematical_form"
http://relativity.livingreviews.org/open?pubNo=lrr-2004-9&page=articlesu25.html"
http://www.astro.ku.dk/~milvang/RelViz/000_node12.html"
http://arxiv.org/PS_cache/gr-qc/pdf/0201/0201080v4.pdf"
http://www.authorstream.com/Presentation/Waldarrama-31254-Kerr-Metric-Rotating-Electrically-Neutral-Black-Holes-Assumptions-Derivation-Abridged-Wh-the-as-Entertainment-ppt-powerpoint/"
 

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  • #2
I have checked the Wikipedia reference, the first two links that you give after Wikipedia, and two references that I happened to take home tonight, and all (including Wikipedia) agree on the form of the Kerr metric.

What most references call [itex]\Delta[/itex], Wikipedia calls [itex]\Lambda^2[/itex]. When these symbol are replaced by their defining expressions, everything works out the same.
 
  • #3
Orion, what do you do/what level are you at career wise. Every post you make is either a question I'm currently working on or have a question about. I feel like we're doing the same thing. Tell me about yourself, maybe we can collaborate.
 

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