Theoretical method for the study of the excited states of a system
  A novel, exact, theoretical method for the study of the excited states of a system is presented. It is demonstrated how to transform the excited state problem of one Hamiltonian into the ground state problem of an auxiliary one. From this, a new exact density functional suitable for excited states is constructed. These results make the excited states of a system accessible through all ground state theoretical techniques. 
Ram\'on Alain Miranda Quintana
quant-ph