Properties of self-localized carriers on a lattice are described at a fairly basic level in this text, with an emphasis on modern developments in the theory of strong-coupling superconductivity.

The properties of self-localized carriers on a lattice are described at a fairly basic level with an emphasis on modern developments in the theory of strong-coupling superconductivity. Large and small polarons and bipolarons provide a number of new physical phenomena both in the normal and superconducting states. The physics of high temperature superconductors is described and explained.