Perturbation theory of symmetric Hamiltonians

E Caliceti, F Cannata, S Graffi
2006 Journal of Physics A: Mathematical and General  
In the framework of perturbation theory the reality of the perturbed eigenvalues of a class of symmetric Hamiltonians is proved using stability techniques. We apply this method to symmetric unperturbed Hamiltonians perturbed by symmetric additional interactions.
doi:10.1088/0305-4470/39/32/s06 fatcat:4dmuxajdo5attjmvkswvmquhgq