具有振动系数的奇摄动算子的第一特征对

Averaging of equations of viscoelasticity with singularly oscillating external forces

Given $ρ\in[0,1]$, we consider for $\varepsilon\in(0,1]$ the nonautonomous viscoelastic equation with a singularly oscillating external force $$ \partial_{tt} u-κ(0)Δu - \int_0^\infty κ'(s)Δu(t-s) d s +f(u)=g_{0}(t)+\varepsilon ^{-ρ}g_{1}(t/\varepsilon ) $$ together with the {\it averaged} equation $$ \partial_{tt} u-κ(0)Δu - \int_0^\infty κ'(s)Δu(t-s) d s +f(u)=g_{0}(t). $$ Under suitable assumptions on the nonlinearity and on the external force, the related solution processes $S_\varepsilon(t,τ)$ acting on the natural weak energy space ${\mathcal H}$ are shown to possess uniform attractors $…

垂直振荡 Neumann 条件的均匀化

Homogenization of a vertical oscillating Neumann condition

本文对垂直振荡 Neumann 边界条件下的 Laplace 和热方程进行均匀化，发现零切向斜率处的钉扎效应，提出奇异各向异性钉扎条件，并建立比较原理证明均匀化，首次在多维 PDE 中展示速率无关钉扎的涌现。

Subcritical perturbation of a locally periodic elliptic operator

We consider a singularly perturbed Dirichlet spectral problem for an elliptic operator of second order. The coefficients of the operator are assumed to be locally periodic and oscillating in the scale $\varepsilon$. We describe the leading terms of the asymptotics of the eigenvalues and the eigenfunctions to the problem, as the parameter $\varepsilon$ tends to zero, under structural assumptions on the potential. More precisely, we assume that the local average of the potential has a unique global minimum point in the interior of the domain and its Hessian is non-degenerate at this point.