I don't understand the general assumptions made during the separation of a single environment of the open system represented by the energy levels into two baths at two temperatures in the diagram below.
Is it assumed that the frequency $\omega_c$ is absent in the spectrum of the hot bath, $\omega_h$ is absent in the cold bath and $\nu$ absent in both?
This is how I picture it when the reservoirs are photon baths:
Is this corrent? Are these conditions the same for phonon baths, i.e. excitation by collisions?
