FeynCalc manual (development version)

FCGetDimensions

FCGetDimensions[expr] is an auxiliary function that determines the dimensions in which 4-momenta and Dirac matrices of the given expression are defined. The result is returned as a list, e.g. {4}, {D} or {4,D,D-4} etc.

This is useful if one wants to be sure that all quantities inside a particular expression are purely 44-dimensional or purely DD-dimensional.

See also

Overview, ChangeDimension.

Examples

FCGetDimensions[GA[i]]

{4}\{4\}

FCGetDimensions[GSD[p]]

{D}\{D\}

FCGetDimensions[FVE[q, \[Mu]] GS[p]]

{4,D4}\{4,D-4\}