Extended Thermodynamics of Phonons
Phonons are much like photons which — as we have seen — are much like atoms of a gas. Infact phonons are much more like particles of a gas than photons, because they can exchange energy and momentum among themselves, which photons cannot do. Because of the similarity to gases it is possible to formulate a kinetic theory of the phonon gas, based on a phonon transfer equation. Peierls ,  was the first to do that. And that equation may serve as the starting point for an extended thermodynamics of phononic moments. This theory was developed by Struchtrup  and Dreyer & Struchtrup .
Unable to display preview. Download preview PDF.