Covariant Hamiltonian Dynamics with Negative Energy States

A relativistic quantum mechanics is studied for bound hadronic systems in the framework of the Point Form Relativistic Hamiltonian Dynamics. Negative energy states are introduced taking into account the restrictions imposed by a correct definition of the Poincar'e group generators. We obtain nonpathological, manifestly covariant wave equations that dynamically contain the contributions of the negative energy states. Auxiliary negative energy states are also introduced, specially for studying the interactions of the hadronic systems with external probes.