Special Session 190: Amplitude equations for continuous, discrete, non-local, and stochastic nonlinear dispersive and dissipative dynamical systems

Amplitude Equations for Nonlocal Swift-Hohenberg Equation
Christian Kuehn
TUM
Germany
Co-Author(s):    
Abstract:
In this talk I am going to present various results regarding the derivation of amplitude equations for nonlocal PDEs. In particular, we shall consider nonlocal reaction terms as well as nonlocal fractional diffusion in the context of the Swift-Hohenberg equation. Interestingly, the resulting Ginzburg-Landau-type amplitude equations become fully local with the non-local influence only entering to leading-order in the coefficients. This shows an interesting decoupling effect near instability. I shall explain, how this effect arises in the proofs as well. The work is based upon the following papers: (1) Validity of amplitude equations for nonlocal nonlinearities, C. Kuehn and S. Throm, Journal of Mathematical Physics, Vol. 59, 071510, 2018. (2) The amplitude equation for the space-fractional Swift-Hohenberg equation, C. Kuehn and S. Throm, Physica D, Vol. 472, 134531, 2025.