Evolution of Gaussian Wave Packet and Nonadiabatic Geometrical Phase for   the time-dependent Singular Oscillator
  The geometrical phase of a time-dependent singular oscillator is obtained in the framework of Gaussian wave packet. It is shown by a simple geometrical approach that the geometrical phase is connected to the classical nonadiabatic Hannay angle of the generalized harmonic oscillator. 
Mustapha Maamache and Hacene Bekkar