What are the Christoffel symbols for the Schwarzschild metric?

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Discussion Overview

The discussion revolves around the calculation of the Christoffel symbols for the Schwarzschild metric, with participants exploring methods for deriving these symbols and their implications for further calculations, such as the Ricci tensor and scalar. The conversation includes technical reasoning and personal experiences with general relativity.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant expresses uncertainty about their calculations of the Christoffel symbols, noting discrepancies with results obtained from Mathematica.
  • Another participant points out that the Schwarzschild solution being a vacuum solution implies that the Ricci tensor and scalar should be zero.
  • A participant inquires about the method used to find the Christoffel symbols, suggesting that brute force from the metric's derivatives is a valid approach.
  • Some participants discuss alternative methods, such as using the Euler Lagrange equations, to derive the geodesic equations and subsequently the Christoffel symbols.
  • One participant admits a lack of knowledge in Lagrangian mechanics, which limits their ability to use that approach.
  • Another participant expresses frustration at not finding a concise tabulation of the Christoffel symbols online and hopes for assistance from others.
  • Concerns are raised about the accuracy of the calculated Christoffel symbols, with one participant providing specific expressions and suggesting potential errors in defining the inverse metric components.
  • A participant shares results from Maxima using the ctensor package, presenting several calculated Christoffel symbols.

Areas of Agreement / Disagreement

Participants generally agree on the implications of the Schwarzschild solution regarding the Ricci tensor and scalar. However, there is no consensus on the accuracy of the calculated Christoffel symbols, and multiple methods and perspectives on deriving them are presented, indicating ongoing uncertainty and debate.

Contextual Notes

Participants express varying levels of familiarity with general relativity and related mathematical techniques, which may affect their approaches and conclusions. There are also indications of potential errors in the calculations of the Christoffel symbols, but these remain unresolved.

Zeron_X25
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I needed some help with the Christoffel symbols for the Schwarzschild metric. I used the metric in wikipedia with signature (+---). For some reason, I get different Christoffel symbols when I use Mathimatica so I'm not sure if it's my calculations that are wrong or not. This isn't homework or anything of the sorts. I'm just trying to find the Ricci tensor and scalar for this metric partly for fun, partly for getting used to the operations and partly to learn more about this metric. In the attached file you'll find the Christoffel symbols that were calculated by me.
Thanks in advance.
 

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The Schwarzschild solution is a vacuum solution, what does that tell you about the Ricci tensor and scalar right off the bat?
 
They should be zero. Sorry that part completely slipped my mind. But my overall goal remains the same nevertheless. I don't seem to be getting the correct Christoffels for some reason.
This is the third metric I'm solving and GR is very new to me so I apologize.
 
Which method are you using to find the Christoffel symbols? Are you just brute forcing it from the equation where they are equal to derivatives of g?
 
I don't know what you mean exactly but I am using the equation, the partials of g.
Is that a wrong approach to this?
 
No, that's a perfectly valid approach, but sometimes other approaches are quicker. For example, you can use the Euler Lagrange equations on the integral \frac{1}{2}\int g_{\mu\nu}\dot{x}^\mu\dot{x}^\nu d\lambda to get the geodesic equations. By comparing with the regular geodesic equations, one can often quickly read off all the Christoffel symbols.
 
Yeah well the problem is that I have no knowledge of Lagrangian mechanics so my hands are quite tied.
 
Interestingly enough, I can't seem to find a nice concise tabulation of the results online...and since I'm way too lazy to try to do this myself, I hope someone else will come along and help you. XD
 
I have all the time in the world. I just want to make sure I get the Christoffel symbols right before I do the Riemann tensor calculation since getting non zero Ricci tensor would mean a lot of wasted time and I hate it when I get stuff wrong after working so hard for it :(
 
  • #10
There are maybe all wrong, for example \Gamma_{00}^1=-\frac{1}{2}g^{11}\partial_r g_{00}=\frac{c^2 r_s (r-r_s)}{2 r^3}
So maybe something is wrong when you define the inverse, e.g. g^{11}=-(1-r_s/r)
 
  • #11
<br /> \begin{align}<br /> {mcs}_{1,1,2}&amp;=\frac{m\,\left( r-2\,m\right) }{{r}^{3}}\\<br /> {mcs}_{1,2,1}&amp;=\frac{m}{r\,\left( r-2\,m\right) }\\<br /> {mcs}_{2,2,2}&amp;=-\frac{m}{r\,\left( r-2\,m\right) }\\<br /> {mcs}_{2,3,3}&amp;=\frac{1}{r}\\<br /> {mcs}_{2,4,4}&amp;=\frac{1}{r}\\<br /> {mcs}_{3,3,2}&amp;=2\,m-r\\<br /> {mcs}_{3,4,4}&amp;=\frac{cos\left( \theta\right) }{sin\left( \theta\right) }\\<br /> {mcs}_{4,4,2}&amp;=-\left( r-2\,m\right) \,{sin\left( \theta\right) }^{2}\\<br /> {mcs}_{4,4,3}&amp;=-cos\left( \theta\right) \,sin\left( \theta\right) <br /> \end{align}<br />

where
<br /> mcs_{abc}={\Gamma^c}_{ab}<br />

and t=x1, r=x2 etc.

This is from Maxima, using the ctensor package.
 

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