The ill-posedness of (non-)periodic travelling wave solution for
deformed continuous Heisenberg spin equation
Abstract
Based on an equivalent derivative nonlinear
Schr\”{o}inger equation, some periodic and non-periodic
two-parameter solutions of the deformed continuous Heisenberg spin
equation are obtained. These solutions are all proved to be ill-posed by
the estimates of Fourier integral in
${H}^{s}_{\mathrm{S}^{2}}$ (periodic
solution in
${H}^{s}_{\mathrm{S}^{2}}(\mathbb{T})$
and non-periodic solution in
${H}^{s}_{\mathrm{S}^{2}}(\mathbb{R})$
respectively). If $\alpha \neq 0$, the
range of the weak ill-posedness index is $1