LorentzIndex[mu]
denotes a -dimensional Lorentz index.
For other than dimensions: LorentzIndex[mu, D]
or LorentzIndex[mu]
etc.
LorentzIndex[mu, 4]
simplifies to LorentzIndex[mu]
.
Overview, ChangeDimension, Momentum.
This denotes a -dimensional Lorentz index.
[\[Alpha]] LorentzIndex
An optional second argument can be given for a dimension different from .
[\[Alpha], n] LorentzIndex