Divergence theorem in curved space

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SUMMARY

The discussion centers on the application of the divergence theorem in curved spacetime within the framework of General Relativity (GR). It establishes that the divergence theorem does not apply straightforwardly in curved spaces, necessitating the use of Killing vectors to define local radial lines for closed curves. The conversation also explores the role of the Landau-Lifgarbagez pseudotensor, which is defined in terms of the Einstein Tensor and the metric, suggesting it represents the net unresolvable apparent force due to spatial curvature. The participants confirm the need for a nuanced understanding of these concepts to accurately interpret gravity in curved spacetime.

PREREQUISITES
  • Understanding of General Relativity (GR)
  • Familiarity with the divergence theorem in flat space
  • Knowledge of Killing vectors and their role in curved spacetime
  • Concept of the Landau-Lifgarbagez pseudotensor
NEXT STEPS
  • Research the application of Killing vectors in General Relativity
  • Study the properties and implications of the Landau-Lifgarbagez pseudotensor
  • Examine various pseudotensors used in GR and their applications
  • Explore the integral form of Gauss's law in the context of curved spacetime
USEFUL FOR

Physicists, mathematicians, and students of General Relativity seeking to deepen their understanding of the divergence theorem and its implications in curved spacetime, as well as those interested in the mathematical descriptions of gravitational phenomena.

utesfan100
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I have been contemplating my confusion about my intuition regarding GR and believe I have tracked down the primary source of confusion.

The classical theories I have been taught assumed flat space with independent time and used the divergence theorem to derive inverse squared laws for fields. Despite GR holding a local form of the differential form of Gauss's law, every attempt to use the integral form is shot down immediately as not conforming to GR.

Am I correct to state that in a curved space the divergence theorem may not apply in a straight forward manner?

It appears that to use the divergence theorem in a curved space time one needs to use something called Killing vectors to define a curvilinear set of local radial lines to define a closed curve around a simply connected region in the curved space. I would think this would allow "local" to be extended from the infinitesimal range of the stress-energy tensor to a finite bounded volume.

Is this the proper interpretation for what the Landau-Lifgarbagez pseudotensor does for GR? ( http://en.wikipedia.org/wiki/Landau-Lifgarbagez_pseudotensor )

Since the Einstein Tensor is proportional to the Stress Energy tensor and also definable in terms of the metric alone it appears that these three tensors are three ways of describing the same mathematical object. Since the Landau-Lifgarbagez pseudotensor is defined in terms of the Einstein Tensor and the metric alone it can be defined in terms of the metric alone, and thus is another description of the same mathematical object.

Am I wrong to think that infinitesimally a pseudotensor represents an apparent force that can be eliminated by a change of reference frame? It would then seem reasonable that the Landau-Lifgarbagez pseudotensor represents the net unresolvable apparent force in a finitely bounded region caused by the spatial curvature in that finite volume.

Is this a correct way to think about gravity?
 
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utesfan100 said:
It references "many psuedo tensors" to do this task, while I have been exposed to only two. What other options exist?

I'm not sure, maybe try http://arxiv.org/abs/hep-th/9310025
 
In an inertial frame of reference (IFR), there are two fixed points, A and B, which share an entangled state $$ \frac{1}{\sqrt{2}}(|0>_A|1>_B+|1>_A|0>_B) $$ At point A, a measurement is made. The state then collapses to $$ |a>_A|b>_B, \{a,b\}=\{0,1\} $$ We assume that A has the state ##|a>_A## and B has ##|b>_B## simultaneously, i.e., when their synchronized clocks both read time T However, in other inertial frames, due to the relativity of simultaneity, the moment when B has ##|b>_B##...

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