feynlag.operators.Dmu

feynlag.operators.Dmu(field, gauge_groups=None)[source]

Covariant derivative of a field: column Matrix over components.

Sign convention (CONVENTIONS.md): D_μ = ∂_μ − i g T^a A^a_μ.

Parameters:

  • field – a Field.

  • gauge_groups – groups to gauge (default: every group in field.reps). Each group’s boson field is created on demand via group.bosons().

Returns:

Matrix (D_μ φ)_i = ∂_μ φ_i − i Σ_G g_G Σ_a A^a_μ (T^a φ)_i.

The Lorentz index is implicit (carried to momentum space by the p(φ) tagging and reconstructed by the vertex classifier).