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U(1), SU(2), SU(3) are symmetry of what?

  1. Feb 11, 2012 #1
    The Standard Model symmetries are U(1), SU(2), and SU(3). But I'm not sure whether these are symmetries of the Action intgral or if they are symmetries of the background spacetime.
     
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  3. Feb 11, 2012 #2

    Fredrik

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    They are symmetries of the action, or equivalently, the Lagrangian. They are not symmetries of spacetime.
     
  4. Feb 11, 2012 #3
    Are these symmetries expected to survive in GR as well as in SR?
     
  5. Feb 11, 2012 #4

    Ben Niehoff

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    Yes, they are gauge symmetries that have nothing to do with the underlying spacetime.
     
  6. Feb 11, 2012 #5
    So is there a diffeomorphic invariant version of the path integral for particle physics that uses the U(1), SU(2), and SU(3) symmetry groups?
     
  7. Feb 12, 2012 #6

    Ben Niehoff

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    The Lagrangian is exactly the same; just replace [itex]\eta_{\mu\nu}[/itex] with [itex]g_{\mu\nu}[/itex].
     
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