Continuous symmetries and conservation laws in chiral media

Locally conserved quantities of the electromagnetic field in lossless chiral media are derived from Noether's theorem, including helicity, chirality, momentum, and angular momentum, as well as the separate spin and orbital components of this last quantity. We discuss sources and sinks of each in the presence of current densities within the material, and in some cases, as also generated by inhomogeneity of the medium. A previously obtained result connecting sources of helicity and energy within chiral materials is explored, revealing that association between the two quantities is not restricted to chiral media alone. Rather, it is analogous to the connection between the momentum, and the spin and orbital components of the total angular momentum. The analysis reveals a new quantity, appearing as the "orbital" counterpart of the helicity density in classical electromagnetism.