Tr

Description

Tr[exp] calculates the Dirac trace of exp. Depending on the setting of the option SUNTrace also a trace over SU(N) objects is performed. Tr is identical toDiracTrace, up to the default setting of DiracTraceEvaluate.

Options[Tr]

See also: DiracSimplify, DiracTrace, FermionSpinSum, SUNTrace.

Examples

GA[μ, ν]

Tr[%]

Tr[(GSD[p] + m) . GAD[μ] . (GSD[q] - m) . 
        GAD[ν]]

Tr[GA[μ, ν, ρ, σ, 5]]

Tr[GAD[μ, ν, ρ, σ, τ, ξ, 5]]

$West

?$West

$West=False should be set before any calculation is done (because intermediate results from trace calculations are cached).

$West = False

Tr[GAD[(Subscript[ν, 1]), (Subscript[ν, 2]), (Subscript[ν, 3]), (Subscript[ν, 4]), (Subscript[ν, 5]), (Subscript[ν, 6])] . 
        GA[5]]

Tr[GS[p, q, r, s]]

Tr[(GS[p] + m) . GA[μ] . (GS[q] + m) . GA[μ], 
      Factoring -> True]

Tr[GA[α, β], FCE -> True]

% // StandardForm

Tr[GAD[μ] . GA[α] . GA[β] . GAD[μ], 
      FCE -> True]

% // StandardForm