3.1 Equilibrium Zero Temperature GREEN's Function

In many-particle problems it is common to use the interaction representation (see Appendix B)

$$\begin{array}{l}\displaystyle \hat{H} \ = \ \hat{H}_0 \ + \ \hat{H}^\mathrm{int} \ , \end{array}$$ (3.1)

where $H_0$ is the non-interacting HAMILTONian and $H^\mathrm{int}$ is the perturbation, which contains all the interactions, i.e. $\hat{H}^\mathrm{int}=\hat{H}_\mathrm{el-el}+\hat{H}_\mathrm{el-ph}$.
M. Pourfath: Numerical Study of Quantum Transport in Carbon Nanotube-Based Transistors