Where Can I Find a Detailed Explanation of Stress-Energy Tensors in GR?

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The discussion centers on the challenges of defining a stress-energy tensor for gravitational fields in General Relativity (GR), emphasizing that local measures of energy-momentum for gravity often yield zero due to coordinate transformations. Participants express confusion over the implications of the covariant divergence of the stress-energy tensor, which is stated to be zero, suggesting a conservation law that seems contradictory when considering energy-momentum exchange with spacetime. The conversation highlights the complexity of gravitational energy, noting that while pseudotensors have been proposed to describe gravitational energy, their validity is debated. Additionally, references to texts like MTW's "Gravitation" and discussions on the equivalence principle are suggested for deeper understanding. The overall consensus is that the concept of gravitational energy remains intricate and elusive within the framework of GR.
  • #91
Jonathan Scott said:
Sorry, I have to admit I don't recall the specific details, but a few years ago when I added up the total LL field energy with the "matter energy" of the source, the total wasn't equal to the rest mass minus the potential energy. I thought perhaps I'd made a mistake in calculating the LL energy density and asked a friend of mine (a professor of physics at Southampton University) to check it; he agreed with my conclusion and found it puzzling, but didn't have time to investigate any further. In contrast, the density given by Lynden-Bell matches up exactly with the semi-Newtonian model.
You certainly have made a mistake. Can you reproduce your calculations in here?
 
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  • #92
samalkhaiat said:
You certainly have made a mistake. Can you reproduce your calculations in here?
It's quite likely that I made a mistake, but that was some time ago and it's unlikely I kept notes for something that didn't work; I certainly don't have them in my file of interesting notes, although I may be able to find some of my correspondence on the subject. I seem to remember the effective field energy density being 7/2 times the square of the Newtonian field instead of 1/2, but that may have been when using a non-equivalent coordinate system.
 
  • #93
samalkhaiat said:
In this case, I suggest you postpone stepping into this treacherous and controversial territory until you finished one of the good textbooks on GR.

Actually I have some doubts here. Which book should I read? Ryder? Zee? Weinberg? Straumann? Carroll? MTW(just kidding!:D)?
I have the problem that since I know things about GR, I become bored on some sections. Also I want a book that covers advanced and exciting topics in a mathematically serious way. So I need a book that, in addition to being good, should be a bit advanced too. Can you suggest one?

samalkhaiat said:
No, you don't. I don't regard myself as "expert". I just know few things.
Its good to be in this forum and see people like you saying such a sentence. Because if I were to only look at the physics students around myself, I would do a really bad mistake in overestimating my level of knowledge!
 
  • #94
Shyan said:
Actually I have some doubts here. Which book should I read? Ryder? Zee? Weinberg? Straumann? Carroll? MTW(just kidding!:D)?
I have the problem that since I know things about GR, I become bored on some sections. Also I want a book that covers advanced and exciting topics in a mathematically serious way. So I need a book that, in addition to being good, should be a bit advanced too. Can you suggest one?
I can only suggest what I believe the golden rule in learning: Read the book that you understand and think it is nice. A book that one finds "good and nice" might not be as "good and nice" for others.
Good luck
 

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