Spatial mapping and time reversal in magnetized compressible media

The invariance of Maxwell´s equations and the equations of motion under orthogonal spatial mapping (rotation, reflection, and inversion) and under time reversal has interesting consequences when the given medium contains a magnetic-field configuration, since the magnetic field reverses its direction both under a reflection mapping and also under time reversal. The warm magnetoplasma which can support both electromagnetic and acoustic wave-fields is well suited for demonstrating equivalence or generalized Lorentz reciprocity relations, which relate electromagnetic and acoustic wave fields and their sources in time-reversed and spatially mapped media when the static magnetic-field configuration has some form of spatial symmetry. Applications include radiation and absorption processes in media immersed in dipole magnetic-field or magnetic-bottle configurations. The use of time reversal (in addition to spatial mapping) yields additional useful results, such as the mapping of ray paths, not immediately evident from the generalized Lorentz reciprocity theorem.