Slow Patterns in Multilayer Dislocation Evolution with Dynamic Boundary Conditions
Yuan Gao, Stefania Patrizi
TL;DR
The paper addresses slow-motion patterns of multilayer dislocation dynamics in a half-plane under a dynamic bulk-boundary coupling, modeled by a multiscale parabolic equation with a nonlinear boundary condition. The authors develop barrier constructions using a multilayer ansatz based on a stationary layer $\phi$ and two correctors $\psi$ and $q$ to capture bulk-interface coupling across all $y\ge0$, proving that the interface centers $z_i(t)$ satisfy the repulsive Peierls–Nabarro ODE $\frac{dz_i}{dt}=\frac{c_0}{\pi}\sum_{j\neq i}\frac{1}{z_i-z_j}$ and that $u_\varepsilon$ converges to a superposition of $N$ transition profiles with explicit boundary trace $\frac{1}{\pi}\sum_i \Big(\frac{\pi}{2}+\arctan\big(\frac{x-z_i(t)}{y}\big)\Big)$. The work connects the fully coupled bulk–interface dynamics to the slow-motion patterns known for the 1D fractional Allen–Cahn equation in the fast-bulk limit, while providing delicate estimates and correctors that stabilize the bulk dynamics for the entire half-plane. The results advance understanding of dislocation dynamics in multi-layer settings and quantify the asymptotics of coupled bulk-interface systems with dynamic boundary conditions. The methodological contribution lies in the barrier framework and the construction of $\psi$ and $q$ to manage the two-way coupling across dimensions and scales.
Abstract
In this paper, we study the slow patterns of multilayer dislocation dynamics modeled by a multiscale parabolic equation in the half-plane coupled with a dynamic boundary condition on the interface. We focus on the influence of bulk dynamics with various relaxation time scales, on the slow motion pattern on the interface governed by an ODE system. Starting from a superposition of N stationary transition layers, at a specific time scale for the interface dynamics, we prove that the dynamic solution approaches the superposition of N explicit transition profiles whose centers solve the ODE system with a repulsive force. Notably, this ODE system is identical to the one obtained in the slow motion patterns of the one-dimensional fractional Allen-Cahn equation, where the elastic bulk is assumed to be static. Due to the fully coupled bulk and interface dynamics, new corrector functions with delicate estimates are constructed to stabilize the bulk dynamics and characterize the limiting behavior of the dynamic solution throughout the entire half-plane.
