The existence and stability of viscosity solutions to perturbed contact Hamilton-Jacobi equations
Huan Wu, Shiqing Zhang
TL;DR
This work establishes the existence and stability of viscosity solutions for perturbed contact Hamilton–Jacobi equations on a compact manifold. By embedding the problem in the weak KAM framework and employing backward solution semigroups, the authors show that a viscosity solution $u_-$ of the unperturbed equation persists under small perturbations as a unique, uniformly convergent solution $u_-^{\varepsilon}$, provided Lyapunov stability and a nondegeneracy condition hold. The analysis leverages the closeness of perturbed and unperturbed Lagrangians, quantitative semigroup estimates, and the implicit action function to control deviations and guarantee convergence. Under a positivity condition on $\partial H/\partial u$ over the calibrated set $\Lambda_{u_-}$, the perturbed problem yields a unique $u_-^{\varepsilon}$ near $u_-$ that retains local Lyapunov asymptotic stability, highlighting robustness of stationary states in dissipative Hamiltonian systems. These results contribute to the understanding of perturbations in contact Hamilton–Jacobi dynamics and extend weak KAM methods to $u$-dependent Hamiltonians with stability guarantees.
Abstract
We consider a contact Hamiltonian $H(x,p,u)$ with certain dependence on the contact variable $u$. If $u_{-}$ is a viscosity solution of the contact Hamilton-Jacobi equation \[H(x,D_{x}u(x),u(x))=0,\quad x\in M,\] and $u_{-}$ is locally Lyapunov asymptotically stable, we will prove that the perturbed equation \[H(x,D_{x}u(x),u(x))+\varepsilon P(x,D_{x}u(x),u(x))=0,\quad x\in M,\] does exist viscosity solution $u_{-}^{\varepsilon}$ which converges uniformly to $u_{-}$, as perturbation parameter $\varepsilon$ converges to 0. Moreover, we give a case that in a neighborhood of viscosity solution $u_-$, the perturbed equation has an unique viscosity solution $u_{-}^{\varepsilon}$. Furthermore, $u_{-}^{\varepsilon}$ keeps locally Lyapunov asymptotically stability.
