On the wave equation with hyperbolic dynamical boundary conditions, interior and boundary damping and supercritical sources

TL;DR

This paper investigates the wave equation with complex boundary conditions, damping, and supercritical sources, establishing local existence, uniqueness, and well-posedness results for challenging nonlinear source terms.

Contribution

It introduces new well-posedness results for wave equations with hyperbolic boundary conditions and supercritical nonlinear sources, extending previous theories.

Findings

Proved local existence and uniqueness of solutions.

Established well-posedness for supercritical source terms.

Analyzed the effects of boundary and interior damping.

Abstract

The aim of the paper is to study the problem $$ \begin{cases} u_{tt}-\Delta u+P(x,u_t)=f(x,u) \qquad &\text{in $(0,\infty)\times\Omega$,} u=0 &\text{on $(0,\infty)\times \Gamma_0$,} u_{tt}+\partial_\nu u-\Delta_\Gamma u+Q(x,u_t)=g(x,u)\qquad &\text{on $(0,\infty)\times \Gamma_1$,} u(0,x)=u_0(x),\quad u_t(0,x)=u_1(x) & \text{in $\bar{\Omega}$,} \end{cases}$$ where $\Omega$ is a bounded open $C^1$ subset of $\mathbb{R}^N$, $N\ge 2$, $\Gamma=\partial\Omega$, $(\Gamma_0,\Gamma_1)$ is a measurable partition of $\Gamma$, $\Delta_\Gamma$ denotes the Laplace--Beltrami operator on $\Gamma$, $\nu$ is the outward normal to $\Omega$, and the terms $P$ and $Q$ represent nonlinear damping terms, while $f$ and $g$ are nonlinear source, or sink, terms. In the paper we establish local and existence, uniqueness and Hadamard well--posedness results when source terms can be supercritical or super-supercritical.