Just wondering if anyone here is familiar with the dynamical Casimir effect? It's part of my dissertation and have a couple of questions. I've read that the photons produced are "always pair-produced from the vacuum in two-mode squeezed states, not in coherent states." Since only one photon is detected can we simply say one is observable while the other is not? Eberlein uses "an adiabatic approximation" in her calculations, this has nothing to do with an adiabatic process (as far as im aware) but is a method used for determining the result. Could someone perhaps give any insight into the term "adiabatic approximation" in terms of quantum mechanics, to what does it infer? thanks for any ideas!