论文标题
时空有限元方法的基础:多面体,插值和集成
Foundations of space-time finite element methods: polytopes, interpolation, and integration
论文作者
论文摘要
本文的主要目的是促进在四维空间中实施时空有限元方法。为了在此设置中开发有限元方法,有必要创建数值基础或等效的数值基础结构。该基础应包括合适的元素(通常是高管,简单或密切相关的多面体),数值插值程序(通常是正规的多项式碱基)以及数值集成程序(通常是正交规则)。众所周知,这些领域中的每个领域尚未得到充分探索,在本文中,我们试图直接解决此问题。我们首先开发一个混凝土,顺序的程序,用于构建通用的四维元素(4-Polytopes)。此后,我们回顾了几个规范元素的关键数值特性:Tesseract,四面体棱镜和五元素。在这里,我们在这些元素上为正常多项式碱基提供明确的表达式。接下来,我们构建具有正权重的完全对称的正交规则,这些规则能够精确整合高度多项式,例如在Tesseract上最多达到17学位。最后,使用一组关于多项式和先验函数的规范数值实验成功测试了正交规则。
The main purpose of this article is to facilitate the implementation of space-time finite element methods in four-dimensional space. In order to develop a finite element method in this setting, it is necessary to create a numerical foundation, or equivalently a numerical infrastructure. This foundation should include a collection of suitable elements (usually hypercubes, simplices, or closely related polytopes), numerical interpolation procedures (usually orthonormal polynomial bases), and numerical integration procedures (usually quadrature rules). It is well known that each of these areas has yet to be fully explored, and in the present article, we attempt to directly address this issue. We begin by developing a concrete, sequential procedure for constructing generic four-dimensional elements (4-polytopes). Thereafter, we review the key numerical properties of several canonical elements: the tesseract, tetrahedral prism, and pentatope. Here, we provide explicit expressions for orthonormal polynomial bases on these elements. Next, we construct fully symmetric quadrature rules with positive weights that are capable of exactly integrating high-degree polynomials, e.g. up to degree 17 on the tesseract. Finally, the quadrature rules are successfully tested using a set of canonical numerical experiments on polynomial and transcendental functions.