Haar measure from a left-invariant coframe

ID: haar-measure-from-a-left-invariant-coframe

On a -dimensional Lie group, take the coframe dual to a basis of left-invariant vector fields. Its top wedge is nonvanishing and invariant under left translations, so its absolute density defines a left Haar measure. If the frame has coordinate matrix , the density is . This makes explicit computation of Haar measure a determinant calculation.

New to topics? Read the docs here!