Enabling four-dimensional conformal hybrid meshing with cubic pyramids

TL;DR

This paper introduces a novel refinement strategy for four-dimensional hybrid meshes using cubic pyramids, along with symmetric quadrature rules for integration, advancing space-time finite element methods.

Contribution

It develops a new conforming refinement strategy for 4D hybrid meshes and introduces symmetric quadrature rules with positive weights for cubic pyramids.

Findings

Refinement subdivides cubic pyramids into congruent shapes.

Quadrature rules integrate polynomials up to degree 12.

Strategy enhances 4D meshing and space-time FEM applications.

Abstract

The main purpose of this article is to develop a novel refinement strategy for four-dimensional hybrid meshes based on cubic pyramids. This optimal refinement strategy subdivides a given cubic pyramid into a conforming set of congruent cubic pyramids and invariant bipentatopes. The theoretical properties of the refinement strategy are rigorously analyzed and evaluated. In addition, a new class of fully symmetric quadrature rules with positive weights are generated for the cubic pyramid. These rules are capable of exactly integrating polynomials with degrees up to 12. Their effectiveness is successfully demonstrated on polynomial and transcendental functions. Broadly speaking, the refinement strategy and quadrature rules in this paper open new avenues for four-dimensional hybrid meshing, and space-time finite element methods.