This book shows how the analytic properties in the complex energy plane of the Green's functions of many particle systems account for the physical effects (level shifts, damping, instabilities) characteristic of interacting systems. It concentrates on general physical principles and, while it does not discuss experiments in detail, includes introductions to topics of current research interest, such as singularities (X-ray, Kondo) associated with transient perturbations in an electron gas, the Mott metal-insulator transition in correlated electron systems, and the phenomenon of high...

This book shows how the analytic properties in the complex energy plane of the Green's functions of many particle systems account for the physical effects (level shifts, damping, instabilities) characteristic of interacting systems. It concentrates on general physical principles and, while it does not discuss experiments in detail, includes introductions to topics of current research interest, such as singularities (X-ray, Kondo) associated with transient perturbations in an electron gas, the Mott metal-insulator transition in correlated electron systems, and the phenomenon of high...