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Einstein Field Equation

  1. Feb 16, 2015 #1
    How to solve EFE without using the vacuum solution like how you did in schwarzschild metric?
  2. jcsd
  3. Feb 16, 2015 #2


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    Education Advisor
    Gold Member

    Do you mean, how to solve the EFE for a general situation? If that is what you mean, probably using numerical methods and a computer.

    If you mean something else, please say what.
  4. Feb 17, 2015 #3
    I am not sure why can we just use the vacuum solution to solve EFE? Why cant we use a nom zero stress momentum tensor to solve?
  5. Feb 17, 2015 #4


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    Staff: Mentor

    The space outside the surface of an object floating in space (like a star or a planet) is vacuum so the stress-energy tensor there is zero. Thus, if we want a solution to the field equations that applies there we set ##T## equal to zero.

    In other problems, for example a ball of dust collapsing under its own gravitational attraction to form a star or planet (google for "Oppenheimer-Snyder"), we don't have a vacuum and the stress energy tensor is not zero. Then we have to solve the field equation for a non-zero stress-energy tensor.
    Last edited: Feb 17, 2015
  6. Feb 17, 2015 #5


    Staff: Mentor

    Another example is the solutions describing the universe as a whole.
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