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A particular representation of gamma matrices

  1. Sep 17, 2011 #1
    I was wondering if there is a representation of gamma matrices unitarily equivalent to the standard representation for wich Dirac Spinors with positiv energy and generic momentum have only the first two component different prom zero. Anyone can help me?
  2. jcsd
  3. Sep 18, 2011 #2


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    yeah, presumably there are lots of representations which are unitarily equivalent to the standard representation... I'm not sure what you are asking? As far as I know unitary equivalence means a matrix A is related to another matrix B via A=UBU^\dagger where U is unitary. So take any unitary matrix U and apply U\gamma_\mu U^\dagger for each mu to generate an equivalent rep.
  4. Sep 19, 2011 #3
    yes I know it. I was wondering what's the representation for which any spinor of positive energy and momentum p have only the first two component different from zero
  5. Sep 19, 2011 #4


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    Isn't that the definition of the Foldy Wouthuysen transformation?
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