Critical Sets of Solutions of Elliptic Equations in Periodic Homogenization

التفاصيل البيبلوغرافية
العنوان: Critical Sets of Solutions of Elliptic Equations in Periodic Homogenization
المؤلفون: Lin, Fanghua, Shen, Zhongwei
سنة النشر: 2022
المجموعة: Mathematics
مصطلحات موضوعية: Mathematics - Analysis of PDEs, 35J15, 35B27
الوصف: In this paper we study critical sets of solutions $u_\e$ of second-order elliptic equations in divergence form with rapidly oscillating and periodic coefficients. We show that the $(d-2)$-dimensional Hausdorff measures of the critical sets are bounded uniformly with respect to the period $\e$, provided that doubling indices for solutions are bounded. The key step is an estimate of "turning " for the projection of a non-constant solution $u_\e$ onto the subspace of spherical harmonics of order $\ell$, when the doubling index for $u_\e$ on a sphere $\partial B(0, r)$ is trapped between $\ell -\delta$ and $\ell +\delta$, for $r$ between $1$ and a minimal radius $r^*\ge C_0\e$. This estimate is proved by using harmonic approximation successively. With a suitable $L^2$ renormalization as well as rescaling we are able to control the accumulated errors introduced by homogenization and projection. Our proof also gives uniform bounds for Minkowski contents of the critical sets.
Comment: Minor revision. Theorem 3.1 is strengthened. The definition of the minimal radius in the proof of Lemma 7.1 is modified
نوع الوثيقة: Working Paper
URL الوصول: http://arxiv.org/abs/2203.13393
رقم الأكسشن: edsarx.2203.13393
قاعدة البيانات: arXiv