Form of Kruskal-Szekeres Completion

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The forum discussion centers on deriving the Kruskal-Szekeres form of the Schwarzschild metric in general relativity, specifically using the Lambert W function. The user struggles with the algebraic manipulation of the equations, particularly in differentiating the radial coordinate 'r' and substituting it into the metric. The final form of the equation presented is dr=2m\frac{dL}{dz}dz, with z=\frac{-uv}{e}. The discussion references a paper by the professor, which provides foundational insights into the derivation process.

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  • Understanding of general relativity concepts, particularly the Schwarzschild metric.
  • Familiarity with the Lambert W function and its applications.
  • Knowledge of differential calculus, especially in the context of multivariable functions.
  • Ability to interpret and manipulate mathematical equations in the context of physics.
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  • Study the derivation of the Schwarzschild metric in detail, focusing on the Kruskal-Szekeres coordinates.
  • Learn about the applications and properties of the Lambert W function in physics.
  • Practice differentiation techniques for functions involving multiple variables.
  • Review the professor's paper linked in the discussion for additional context and methodologies.
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This discussion is beneficial for students and researchers in theoretical physics, particularly those studying general relativity and the mathematical techniques used in metric derivations.

Airsteve0
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In my general relativity class my professor derived the form of the Kruskal-Szekeres form of the Schwarzschild metric using several formulas without actually going through the algebra. I am trying to prove the answer using these formulas but I am having some trouble, especially using the Lambert W. function. In the file I have attached, you can see that equation (9) is the final result from the changes made in the previous equations. In my attempt I tried taking the derivative of the equation for 'r' and arrived at what I have shown below. However, when subbing this in and working with this I don't feel I am making progress. Any assistance is greatly appreciated, thanks.

dr=2m\frac{dL}{dz}dz

where z=\frac{-uv}{e}

The link for my professor's paper is at this link, http://arxiv.org/pdf/1202.0860v2.pdf , but I will also include the .pdf
 

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That seems like a proper mess :)

But basically what you have is
r = 2m(\mathcal{L}(1+\Psi(u,v)))
so
dr = \frac{\partial r}{\partial u} du + \frac{\partial r}{\partial v} dv = ... = \frac{2m \mathcal{L}}{1 + \mathcal{L}} (du/u + dv/v)
or something like that; I'm too lazy to do the work :) Then repeat for dt. Then you just plug them into the metric and pray everything works out.
 
got it, thanks!
 

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