This is just an example of an important property of Lie Group tensor operators. It means that the tensor operator $\gamma^{\mu}$ transforms like a 4-vector under conjugation.

Please see my answer to "Do the Dirac matrices form a proper four-vector?" which might have been better posted here.

This is just an example of an important property of the GL(N) Lie Group tensor operators. It means that the tensor operator $\gamma^{\mu}$ transforms like a 4-vector under conjugation.

Please see my answer to "Do the Dirac matrices form a proper four-vector?" which might have been better posted here.