Note on Energy Shifts of Oscillators in Blackbody Radiation

TL;DR

This paper calculates the energy shifts of oscillators in blackbody radiation based on the total energy of the system, confirming previous high-temperature results and highlighting the dependence on the refractive index.

Contribution

It provides a simple calculation method for energy shifts in blackbody radiation systems, extending previous work by explicitly relating shifts to the refractive index.

Findings

Energy shift varies as -T^2 at high temperatures.

Free-energy shift varies as +T^2 at high temperatures.

Results agree with earlier findings by Ford, Lewis, and O'Connell.

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)].