A geometric approach to time evolution operators of Lie quantum systems
  Lie systems in Quantum Mechanics are studied from a geometric point of view. In particular, we develop methods to obtain time evolution operators of time-dependent Schrodinger equations of Lie type and we show how these methods explain certain ad hoc methods used in previous papers in order to obtain exact solutions. Finally, several instances of time-dependent quadratic Hamiltonian are solved. 
Jos\'e F. Cari\~nena, Javier de Lucas and Arturo Ramos