Periodic weak solutions for a classical one-dimensional isotropic biquadratic Heisenberg spin chain

In this paper, we consider the model proposed by Lakshmanan, Porsezian and Daniel [M. Lakshmanan, K. Porsezian, M. Daniel, Effect of discreteness on the continuum limit of the Heisenberg spin chain, Phys. Lett. A 133 (1988) 483–488] describing the continuum isotropic biquadratic Heisenberg spin chain in one dimensional case. Following the results of integrability in [K. Porsezian, M. Daniel, M. Lakshmanan, On the integrability aspects of the one-dimensional classical continuum isotropic Heisenberg spin chain, J. Math. Phys. 33 (5) (1992) 1807–1816], we prove the existence of periodic weak solutions to this model.