Well-Posedness and Long-Time Dynamics of a Water-Waves Model with Time-Varying Boundary Delay
G. Bautista, R. de A. Capistrano--Filho, B. Chentouf, O. Sierra Fonseca
TL;DR
The paper addresses well-posedness and long-time dynamics of a fifth-order Boussinesq-type water-waves model with a time-varying boundary delay. It combines Kato's variable-norm framework and a transposition-based fixed-point approach to prove local well-posedness for small initial data, and constructs a Lyapunov functional to establish exponential decay for the linearized delayed system. Under explicit param and delay-structure conditions, it also derives an optimal decay rate via a careful optimization of the Lyapunov constants. The results extend previous work by incorporating additional high-order nonlinearities and a delay at the boundary, with implications for stabilization of dispersive systems with time-varying delays. The work highlights both the potential for rapid stabilization in delayed dispersive models and the challenges in extending these results to global-in-time nonlinear dynamics.
Abstract
A higher-order nonlinear Boussinesq system with a time-dependent boundary delay is considered. Sufficient conditions are presented to ensure the well-posedness of the problem by utilizing Kato's variable norm technique and the Fixed-Point Theorem. More significantly, the energy decay for the linearized problem is demonstrated using the energy method.
