In this paper, a system with spin S=3/2 with general isotropic nearest neighbor exchange within a mean field approximation possess is discnssed. We derive equations describing non-Heisenberg isotropic model using coherent states of SU(4) group in real parameters and then obtain dispersion equations of spin wave of dipole and quadrupole branches for a small linear excitation from the ground state.

 We consider Bethe-Salpeter (BS) equation for the bound state of two point particles in the non-commutative space-time. We subsequently explore the BS equation for spin0-spin0, spin1/2-spin1/2 and spin0-spin1/2 bound states. we show that the lowest order spin independent correction to energy spectrum in each case is of the order θ a 4 while the spin dependent one in NC space, is started at the ...