Cluster properties in Poincare invariant quantum mechanics
  Using a simple model we provide a quantitative study of the size of the corrections needed to restore cluster properties to the construction of Poincare invariant dynamical models with kinematic spins, first provided by B. Bakamjian and L. H. Thomas. Our model calculations suggest that these corrections are too small to have a quantitative impact on nuclear physics observables calculated using models with meson and nucleon degrees of freedom. 
W. N. Polyzou and B. D. Keister
nucl-th