For an electron-phonon system with several equivalent bands a closed set of integral equations is solved self-consistently using real-time Green's functions. A multiple-band Peierls-Boltzmann equation is deduced from the Bethe-Salpeter equation for the electron density. Relaxation-time...

We construct a thermodynamic model for a system of electronic d-bands coupled to the elastic lattice. For the electronic fluctuations a Debye-type of relaxation, for the lattice displacement a modified elastic equation of motion is assumed. As a result a coupling of certain acoustic and...