Pseudogap in one dimension

Two decades ago, Sadovskii found an exact solution for a model describing a pseudogap in electron energy spectrum (introduced by Lee, Rice, and Anders on). The discovery of a pseudogap in high-T-c superconductors has revived i nterest in his exact solution. I review the model with the emphasis on phys ical content, point out an error in the original Sadovskii solution, and ex plain which problem he actually solved. A recent incorporation of Sadovskii 's ideas into a description of "hot spots" on the Fermi surface in cuprate superconductors (Schmalian, Pines, and Stojkovic) is briefly discussed. [S0 163-1829(99)01802-0].