摘要:The Hubbard-Holstein model is a simple model including both electron-phonon interaction and
electron-electron correlations. We review a body of theoretical work investigating, the effects of
strong correlations on the electron-phonon interaction. We focus on the regime, relevant to high-𝑇𝑐 superconductors, in which the electron correlations are dominant. We find that electron-phonon
interaction can still have important signatures, even if many anomalies appear, and the overall
effect is far from conventional. In particular in the paramagnetic phase the effects of phonons are
much reduced in the low-energy properties, while the high-energy physics can still be affected by
phonons. Moreover, the electron-phonon interaction can give rise to important effects, like phase
separation and charge-ordering, and it assumes a predominance of forward scattering even if the
bare interaction is assumed to be local (momentum independent). Antiferromagnetic correlations
reduce the screening effects due to electron-electron interactions and revive the electron-phonon
effects.