Note on Energy Shifts of Oscillators in Blackbody Radiation
Peter Milonni
Abstract
The energy shift of an oscillator in blackbody radiation is calculated based simply on the total energy of the interacting field-oscillator system as a function of the refractive index. For high temperatures T the energy and free-energy shifts are found to vary as -T^2 and +T^2, respectively, in agreement with the result originally obtained by Ford, Lewis, and O'Connell [Phys. Rev. Lett. 55, 2273 (1985)].