Three-magnon process in the one-dimensional integer spin antiferromagnetic Heisenberg chain

We present a calculation of the correlation function in time for the integer spin S one-dimensional antiferromagnet taking into account three-magnon process. The procedure includes two-magnon and three-magnon processes in the dynamic structure factor using a modified spin wave theory. We show that the inclusion of the three-magnon process does not change the double peak structure obtained for the Dynamical Structure Factor.