CHARGE-SPIN SEPARATION AND THE SPECTRAL PROPERTIES OF LUTTINGER LIQUIDS

We compute the spectral function rho(q,omega) of the one-dimensional L uttinger model. We discuss the distinct influences of charge-spin sepa ration and of the anomalous dimensions of the fermion operators and th eir evolution with correlation strength. Charge-spin separation shows up in finite spectral weight at frequencies between upsilon(sigma)q an d upsilon(rho)q, where upsilon(sigma) and upsilon(rho) are the velocit ies of spin and charge fluctuations, while spectral weight above upsil on(rho)q and below -upsilon(rho)q is generated by the hybridization of the Fermi surface at +/-k(F) by interactions. There are nonuniversal power-law singularities at these special frequencies. We discuss the c onsistency of recent photoemission experiments on Low-dimensional cond uctors with a Luttinger-liquid picture, which then would suggest very strong long-range interactions. It is pointed out that many-particle c orrelation functions in principle exhibit similar singularities, but t hey probe different and complementary aspects of the Fermi-surface int eractions.