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LScalarQ

LScalarQ[expr]
gives True if expr is a Lorentz scalar expression, and False otherwise. Assigning LScalarQ[symb]=True declares symb to be a Lorentz scalar.

Details and OptionsDetails and Options

  • An expression is considered a Lorentz scalar if it is a numeric quantity, or if it also contains symbols that are known Lorentz scalars.
  • LScalarQ is used during expression manipulation by LTensor, LDot, and other related functions.
  • A symbol can be declared a Lorentz scalar explicitly with LScalarQ[symb]=True.

ExamplesExamplesopen allclose all

Basic Examples  (2)Basic Examples  (2)

Number of spacetime dimensions is a Lorentz scalar:

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Generic symbols are not known to be Lorentz scalars:

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Without further information, it is not possible distinguish generic symbols as scalars or as vectors:

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Declare m to be a Lorentz scalar:

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m will now be consistently factored out of LDot and LTensor:

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