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arXiv 1203.0908math.PR
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离散椭圆型方程随机均匀化的最优误差估计

An optimal error estimate in stochastic homogenization of discrete elliptic equations

Antoine Gloria, Felix Otto

摘要:

本文是姊妹文章[安。39(2011)779- 856]。我们考虑$d$维格点$\mathbb{Z}^d$上的离散椭圆方程,随机系数$A$为最简单的类型:它们同分布且边到边独立。在大型w.r.t.晶格间距(即,单位),已知解算子表现得像具有常数确定性系数的(连续)椭圆方程的解算子。该对称“均匀化”矩阵$A_{\mathrm{hom}}=a_{\mathrm{hom}}\mathrm{Id}$的特征在于对于任何方向$ξ\in\mathbb{R}^d$的$ξ\cdot A_{\mathrm{hom}}ξ=<(ξ+\nablaϕ)\cdot A(ξ+\nablaϕ)>$,其中随机场$ϕ$(“校正器”)是$-\nabla^*\cdot A(ξ+\nablaϕ)=0$在$\mathbb{Z}^d$中的唯一解,使得$ϕ(0)=0$、$\nablaϕ$是固定的,并且$<\nablaϕ>=0$、$<\cdot>$表示系综平均(或期望)。

英文摘要:

This paper is the companion article to [Ann. Probab. 39 (2011) 779--856]. We consider a discrete elliptic equation on the $d$-dimensional lattice $\mathbb{Z}^d$ with random coefficients $A$ of the simplest type: They are identically distributed and independent from edge to edge. On scales large w.r.t. the lattice spacing (i.e., unity), the solution operator is known to behave like the solution operator of a (continuous) elliptic equation with constant deterministic coefficients. This symmetric "homogenized" matrix $A_{\mathrm{hom}}=a_{\mathrm{hom}}\mathrm{Id}$ is characterized by $ξ\cdot A_{\mathrm{hom}}ξ=<(ξ+\nablaϕ)\cdot A(ξ+\nablaϕ)>$ for any direction $ξ\in\mathbb{R}^d$, where the random field $ϕ$ (the "corrector") is the unique solution of $-\nabla^*\cdot A(ξ+\nablaϕ)=0$ in $\mathbb{Z}^d$ such that $ϕ(0)=0$, $\nablaϕ$ is stationary and $<\nablaϕ>=0$, $<\cdot>$ denoting the ensemble average (or expectation).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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