  The formation and possible decay processes of neutral and charged excitonic
complexes in electronic integral and fractional quantum Hall systems are
discussed. The excitonic complexes are bound states of a small number of the
relevant negatively and positively charged quasiparticles (e.g., conduction
electrons and valence holes, reversed-spin electrons and spin holes, Laughlin
quasielectrons and quasiholes, composite Fermions) that can occur in a 2D
electron in the presence of a strong magnetic field. Examples of such bound
states are interband neutral and charged excitons, fractionally charged "anyon
excitons", spin waves, skyrmions, or "skyrmion excitons". Possible decay
processes include radiative recombination, experimentally observed in
photoluminescence or spin transitions, important in the context of nuclear spin
relaxation.
