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arXiv 0712.3671math.APcs.NAmath.NA
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散度形式椭圆算子Dirichlet问题的单调数值格式

Monotone Numerical Schemes for a Dirichlet Problem for Elliptic Operators in Divergence Form

University of Zagreb(萨格勒布大学)

Nedzad Limić, Mladen Rogina

AI总结:

针对散度形式椭圆算子的Dirichlet问题,构造基于非标准模板的单调数值格式,并证明其在W_2^1、C和L_1空间中的收敛性。

摘要:

考虑一个二阶微分算子 $A(\msx) = -\:\sum_{i,j=1}^d \partial_i a_{ij}(\msx) \partial_j \:+\: \sum_{j=1}^d \partial_j ig(b_j(\msx) \cdot ig)\:+\: c(\msx)$ 在 ${\bbR}^d$ 上,在有界区域 $D$ 上具有Dirichlet边界条件,扩散张量 $a_{ij}$ 的系数满足温和假设。目标是构造单调数值格式来逼近问题 $A(\msx) u(\msx) \: = \: μ(\msx), \quad \msx \in D$ 的解,其中 $μ$ 是一个正Radon测度。我们首先简要提及存在性和唯一性问题,引入证明收敛性所需的函数空间。然后,我们在网格节点上定义非标准模板,通过具有分区结构的矩阵得到扩展的离散化格式。接着进行椭圆算子的离散化,从常扩散张量开始,到散度形式的算子。最后,我们详细讨论 $W_2^1$-收敛性,并提及 $C$ 和 $L_1$ 空间中的收敛性。我们通过一个数值例子说明格式和收敛性结果。

英文摘要:

We consider a second order differential operator $A(\msx) = -\:\sum_{i,j=1}^d \partial_i a_{ij}(\msx) \partial_j \:+\: \sum_{j=1}^d \partial_j \big(b_j(\msx) \cdot \big)\:+\: c(\msx)$ on ${\bbR}^d$, on a bounded domain $D$ with Dirichlet boundary conditions on $\partial D$, under mild assumptions on the coefficients of the diffusion tensor $a_{ij}$. The object is to construct monotone numerical schemes to approximate the solution to the problem $A(\msx) u(\msx) \: = \: μ(\msx), \quad \msx \in D$, where $μ$ is a positive Radon measure. We start by briefly mentioning questions of existence and uniqueness, introducing function spaces needed to prove convergence results. Then, we define non-standard stencils on grid-knots that lead to extended discretization schemes by matrices possesing compartmental structure. We proceed to discretization of elliptic operators, starting with constant diffusion tensor and ending with operators in divergence form. Finally, we discuss $W_2^1$-convergence in detail, and mention convergence in $C$ and $L_1$ spaces. We conclude by a numerical example illustarting the schemes and convergence results.

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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