ON QUANTUM RADIATION FROM A MOVING BODY WITH FINITE REFRACTIVE-INDEX

Radiation from moving mirrors, a dynamic counterpart to the Casimir effect, is peculiar to quantum physics. Most earlier treatments consider only perfectly reflecting bodies, which need notoriously sophisticated and ad hoc methods. By deliberate contrast we study a Hamiltonian formalism requiring only the most elementary version of field quantization. It is applied to a one-dimensional scalar model with just one body, relying, however, only on methods readily generalized to higher dimensions and to the Maxwell field. The body can have any finite (but nondispersive) refractive index n; for speeds well below c but otherwise arbitrary, one needs only a judicious blend of simple perturbative and adiabatic approximations. They yield the spectrum, the total radiated energy, the radiative reaction force F, and its distribution over the body. The perfect-reflector limit n → ∞ can be taken in all end-results: It gives a dissipative part of F agreeing with previous calculations, and another part renormalizing the mass of the body, reported by some but not all other workers. © 1993 Academic Press, Inc.