RIXS dynamics for beginners

The dynamics in resonant inelastic scattering is reviewed. Simplifying pictures and basic conservation rules are used as starting point for the discussion, rather than a rigorous theoretical framework. It is emphasized that selectivity in terms of energy land to some extent momentum and angular momentum) of the incoming photon has changed the perspective on core level spectroscopies during the last decade. Dynamics on the femtosecond timescale can be studied by comparing rates of competing processes and analysis of interference effects. (C) 2000 Elsevier Science B.V. All rights reserved.