ELECTROMAGNETISM IN NON-INERTIAL COORDINATES

The electromagnetic equations are expressed in a form appropriate to an observer in arbitrary motion in flat spacetime. The field equations preserve their form, dependence on the motion being confined to the material constitutive relations which are assumed linear and non-dispersive. The 4-metric is uniquely defined by the geometry of the observer's worldline. Two conceivable metrics for the 3-space are noticed and the choice judged unimportant for most purposes. An equation for the eikonal of geometrical optics is found and an approximate solution exhibits the leading contributions that are made to the optical length of a ray by the observer's angular velocity and translational acceleration, the former contribution being independent of the refractive index of material traversed by the ray and at rest in the observer's coordinate system.