Special Session 19: 

Time-periodic problem for the complex Ginzburg-Landau equation with non-dissipative nonlinearities on bounded domains

TAKANORI KURODA
Waseda University
Japan
Co-Author(s):    Mitsuharu \^Otani (Professor emeritus at Waseda University)
Abstract:
In this talk, we consider the complex Ginzburg-Landau equation (CGL) with non-dissipative nonlinearities of the form: \[ \frac{\partial u}{\partial t}(t,x)-(\lambda+i\alpha)\Delta u-(\kappa+i\beta)|u|^{q-2}u-\gamma u=f(t,x) \] on bounded domains \(\Omega\) with smooth boundaries. Here \(i=\sqrt{-1}\) denotes the imaginary unit; parameters \(\lambda\) and \(\kappa\) are positive; \(\alpha\), \(\beta\) and \(\gamma\) are real. Under the Sobolev subcritical condition on \(q\) and a suitable assumption on \(\gamma\) depending on \(\lambda\) and the first eigenvalue of the Laplace operator with the homogeneous Dirichlet boundary condition on \(\Omega\), we show that there exists a periodic solution with period \(T>0\) of (CGL) for given sufficiently small external forces \(f\) defined on \([0,T]\). Our method is based on the theory developed in \^Otani (1984), which shows a large applicability to ensure the existence of periodic solutions for nonlinear evolution equations of parabolic type. The theory employs Schauder`s fixed point theorem based on the strong relative boundedness of perturbations compared with the principal term, while the term \(-i\alpha\Delta u\) is not dominated by the parabolic principal term \(-\lambda\Delta u\). So that we use the monotonicity of \(-i\alpha\Delta u\) in order to deal with this difficulty.