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After finding the Einstein Tensor

  1. Apr 12, 2009 #1
    Before I begin, I stress that this is NOT a homework question but rather a self-study question.

    In any case, I calculated the Einstein Tensor of a body with the metric diag[{2GM/r-1,0,0,0},{0,1+2GM/r,0,0},{0,0,1+2GM/r,0},{0,0,0,1+2GM/r}]. What does the Einstein Tensor represent? Does its determinant/trace/or matrix operations have any physical meaning?
     
  2. jcsd
  3. Apr 12, 2009 #2

    atyy

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    The covariant derivative of the Einstein tensor is zero, which by the Einstein field equation means the covariant derivative of the stress-energy-momentum tensor is zero, which is related to energy-momentum conservation in flat spacetime.
     
  4. Apr 17, 2009 #3
    Basically, the Einstein tensor is a trace-reversed version of the Ricci tensor (a contraction of the Riemann curvature tensor). Its most salient feature is that it is conserved, in the following sense: [tex] G^{ab}_{;b} = 0 [/tex]. In other words, the "divergence" of the Einstein tensor vanishes.
     
  5. Apr 17, 2009 #4
    As was mentioned indirectly; the Einstein tensor is physically identified with the physical stress-energy tensor. The physical properties associated with the Stress-Energy tensor are explained in various books. The wikipedia article seems adequate:
    http://en.wikipedia.org/wiki/Stress-energy_tensor

    Ray
     
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