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DiracS

LTensor[DiracS,μ,ν] or σμ,ν
represents the gamma matrix commutator .

Details and OptionsDetails and Options

  • DiracS is recognized as an object in spinor space by Spur and FermionLineExpand.
  • DiracS can be entered in StandardForm as σ using EscsEsc.
  • The FullForm of σμ,ν is LTensor[DiracS,μ,ν].
  • Four-vectors contracted into DiracS appear as indices set in braces {}.
  • The indices of DiracS are ordered automatically.
  • Although the symbol σ can be used in other ways, such as an index in εμ,ν,ρ,σ, using different symbol like ς is prefered. »

ExamplesExamplesopen allclose all

Basic Examples  (3)Basic Examples  (3)

A trace with sigma-matrix:

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All objects in spinor space should be entered inside Spur or DiracMatrix. Otherwise, symbols outside Spur or DiracMatrix are always assumed to commute, and can lead to surprising results:

In[1]:=
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