  A general introduction to the anyon model (braid group, Chern-Simons
Lagrangian and Aharonov-Bohm Hamiltonian formulations) is given. A review
follows on exact results and possible ways of getting additional information,
as mean field approach, perturbation theory, and projection on the lowest
Landau level of an external magnetic field. To be published in Mesoscopic
Quantum Physics - Les Houches, Session LXI, 1994 - E. Akkermans, G. Montambaux
and J.-L. Pichard, eds. - North- Holland, Amsterdam.
