Photon absorption by an accelerated atom

1. Feb 3, 2007

Leo.Ki

I'm wondering whether QM considers photon absorption by an accelerating atom as an instantaneous event, or the change in velocity (and proper time) of the atom affects the perceived distribution of the wave packet and the outcome of the process. In other words, is there a "Doppler gradient" affecting the absorption? Thanks!

2. Feb 4, 2007

Schrodinger's Dog

I'm no expert but an atom will absorb energy at specifc quanta according to the energy levels of it's electrons, assuming you know the energy levels of each electron, then the photon of this precise level will be absorbed at this frequency, I don't think the doppler effect makes any difference as the energy of the atom is what is important, but as I said I am no expert. I could be mistaken, but I assume that the atoms speed means that the only difference is in absorption time I supose for speeds close to c? Anyway I'm sure someone more knowledgeable could answer this.

3. Feb 4, 2007

Leo.Ki

Thanks, Schrödinger's Dog. The problem is that the frequency of the incident photon is constant only for an inertial frame. Unless the acceleration of the atom is caused by gravity, the atom is not likely to accelerate as a whole block. Moreover any acceleration is quantized in tiny jerks if I understand right. Is it assumed that the absorption occurs during a lapse of time during which the atom is considered inertial, or does it span over several frames?