Point-Coupling Models from Mesonic Hypermassive Limit and Mean-Field   Approaches
  In this work we show how nonlinear point-coupling models, described by a Lagrangian density that presents only terms up to fourth order in the fermion condensate $(\bar{\psi}\psi)$, are derived from a modified meson-exchange nonlinear Walecka model. The derivation can be done through two distinct methods, namely, the hypermassive meson limit within a functional integral approach, and the mean-field approximation in which equations of state at zero temperature of the nonlinear point-coupling models are directly obtained. 
O. Louren\c{c}o, M. Dutra, R. L. P. G. Amaral, and A. Delfino
nucl-th