Metric Form of ##g_{μν}## - Solving a Challenge

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Discussion Overview

The discussion revolves around the metric form of ##g_{μν}## as presented in a specific equation, with participants seeking clarification on how to interpret or manipulate this metric in the context of general relativity. The conversation includes questions about the meaning of "solving" the metric and how it relates to equations of motion.

Discussion Character

  • Debate/contested
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant presents a metric equation and asks how to "solve" it, which prompts confusion among others regarding the meaning of "solve" in this context.
  • Several participants point out that the equation is simply a statement of a metric and lacks definitions for certain variables, such as ##l##.
  • There are repeated requests for context regarding the origin of the equation, including references to an article that contains the metric.
  • Another participant inquires about the meaning of specific terms in a related equation involving derivatives and the determinant of the metric.
  • Some participants express frustration over the lack of clarity in the original question and the need for more foundational knowledge in general relativity.
  • There are requests for the form of ##g_{μν}## that can be substituted into an equation of motion, indicating a desire for a specific representation of the metric.
  • One participant suggests that the components of ##g_{μν}## can be read directly from the line element, questioning the difficulty others are experiencing.

Areas of Agreement / Disagreement

Participants generally do not agree on the interpretation of "solving" the metric, with multiple competing views on what the original poster is seeking. The discussion remains unresolved regarding the specific needs of the original questioner.

Contextual Notes

There are limitations in the discussion due to missing definitions and assumptions, particularly regarding the variable ##l## and the context of the metric. The participants also highlight the need for clearer communication and understanding of LaTeX formatting.

hykhor0601
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TL;DR
Does anyone know how to solve this?
##ds^2=g_{μν}(x)dx^μdx^ν= -(r^6/l^6)[1-(Ml^2/r^2)]dt^2+{1/[(r^2/l^2)-M]}dr^2+r^2dΦ^2##

Does anyone know how to solve this?
 
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What do you mean by "solve"? There is nothing to "solve", there is just a line-element.
 
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Solve in what sense? It appears to be just a statement of a metric, missing a definition of ##l## and assuming ##d\Phi## is a solid angle element.
 
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Can you provide some context here? Where di this equation come from? What book course etc...?

and what have you tried so far?

We had to modify your equation using Latex to make it readable:
ds^2=gμν(x)dx^μdx^ν= -(r^6/l^6)[1-(Ml^2/r^2)]dt^2+{1/[(r^2/l^2)-M]}dr^2+r^2dΦ^2

Basically the changes were to bracket the equation on both sides with double # and to replace the gμν with g_{μν} to make them into subscripts.
 
jedishrfu said:
Can you provide some context here? Where di this equation come from? What book course etc...?

and what have you tried so far?

We had to modify your equation using Latex to make it readable:Basically the changes were to bracket the equation on both sides with double # and to replace the gμν with g_{μν} to make them into subscripts.
https://arxiv.org/pdf/0909.1347.pdf The metric is given in (9)
 
Ibix said:
Solve in what sense? It appears to be just a statement of a metric, missing a definition of ##l## and assuming ##d\Phi## is a solid angle element.
The conditions is in the article below, please help me
https://arxiv.org/pdf/0909.1347.pdf
 
hykhor0601 said:
The conditions is in the article below, please help me
https://arxiv.org/pdf/0909.1347.pdf
This still does not answer the question you have been asked about what you mean by ”solve”.
 
∂∨μ[(√-g)g∨μν∂∨ν(Φ)]-m^2√(-g)Φ=0
What is the meaning of ∂∨μ,√-g,∂∨ν(Φ) in this equation?

How to give the form of g^μν from the metric (9) in the article?(or how do i get the form of ∂∨μ[(√-g)g∨μν∂∨ν(Φ)]-m^2√(-g)Φ=0 )
https://arxiv.org/pdf/0909.1347.pdf
Please help me, thank you
 
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hykhor0601 said:
The conditions is in the article below, please help me
https://arxiv.org/pdf/0909.1347.pdf
Again, what do you mean by "solve"? The metric is not a thing you solve. What are you trying to find out?
 
  • #10
Why are you interested in this particular paper if you are not familiar with basics of general relativity?
 
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  • #11
Ibix said:
Again, what do you mean by "solve"? The metric is not a thing you solve. What are you trying to find out?
just the form of gμν that can be sub into the equation of motion
 
  • #12
hykhor0601 said:
just the form of gμν that can be sub into the equation of motion
You already have ##g_{\nu\nu}##. What is your actual problem?
 
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  • #13
Orodruin said:
You already have ##g_{\nu\nu}##. What is your actual problem?
can you write it in the form after substitude into
∂µ[√ (−g)gµν∂ν(ϕ) ]− m^2√ (−g)ϕ = 0
 
  • #14
I don't understand. You can read off the components of ##g_{\mu\nu}## from the line element and ##g## is just its determinant. Where's the difficulty?

It would also help immensely if you spent a few minutes reading the LaTeX Guide linked below the reply box. Then you could type maths in a way that we could actually read it.
 
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