Scalar field equation with torsion induced non linearity: aspects of solutions in RW and Minkowski space-time

A massive scalar field equation with non linear torsion induced term, is studied in a form slightly different from the one previously considered. The object is of both discussing solutions of the equation and suggesting physical interpretation. In the Robertson-Walker metric a variable separation method is applied in analogy of what done for non linear spin 1/2 and 1 field equation in RW metric. The angular separated equation is suitably integrated and the time and radial dependence further discussed. In the Minkowski space time, solutions that are small perturbations of plane waves solutions are discussed. In the given approximation, the perturbation produces a modification of both the velocity of propagation and, more sensibly, of the amplitude of the unperturbed solution.