Berry phase correction to electron density in solids and "exotic"   dynamics
  Recent results on the semiclassical dynamics of an electron in a solid are explained using techniques developed for ``exotic'' Galilean dynamics. The system is indeed Hamiltonian and Liouville's theorem holds for the symplectic volume form. Suitably defined quantities satisfy hydrodynamic equations. 
C. Duval, Z. Horvath, P. A. Horvathy, L. Martina, P. Stichel