Electron-phonon pairing in the Hubbard model

This paper reports that a system of electrons with strong correlations is considered within the framework of a single-band Hubbard model with a strong anharmonic electron-phonon interaction. The dependence of superconducting transition temperature Tc on carrier concentration n is obtained using the Green function technique. It is shown that, due to the nonlocal character of electron-phonon coupling in the model, Tc(n) strongly depends on the symmetry of the gap