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arXiv 2302.08034math.NAcs.NAmath.APphysics.comp-phphysics.flu-dynphysics.plasm-ph
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超越 Strang:对一些二阶 3-分裂方法的实用评估

Beyond Strang: A practical assessment of some second-order 3-splitting methods

Raymond J. Spiteri, Arash Tavassoli, Siqi Wei, Andrei Smolyakov

AI总结:

本文评估了若干替代 Strang 的二阶 3-算子分裂方法,在 Brusselator 和 Vlasov–Poisson 问题上实现了 10%–20% 的效率提升,并提出了包含计算成本的实用评估框架。

摘要:

算子分裂是一种流行的求解微分方程的分而治之策略。通常,微分方程的右端项被分裂成若干部分,然后分别进行积分。已知有许多方法可以将右端项分裂成两部分。然而,这种方法存在局限性,并且在某些情况下,3-分裂更为自然且最终更具优势。二阶 Strang 算子分裂方法可以很容易地推广到将右端项分裂成任意数量的算子。由于其高效性、易于实现和直观性,它可以说是最流行的 3-分裂方法。其他 3-分裂方法虽然存在,但知名度较低,并且对其实际性能的分析和评估十分匮乏。我们在两个问题上展示了 Strang 分裂的一些替代性 3-分裂二阶方法的有效性:反应-扩散 Brusselator 问题,该问题可以分裂成三个部分,且每个部分都有闭式解;以及用于半拉格朗日等离子体模拟的动力学 Vlasov–Poisson 方程。我们发现替代性的二阶 3-算子分裂方法相比传统 Strang 分裂实现了 10%–20% 的效率提升。我们对算子分裂方法效率的实用评估分析包含了积分器的计算成本,可用于方法设计。

英文摘要:

Operator splitting is a popular divide-and-conquer strategy for solving differential equations. Typically, the right-hand side of the differential equation is split into a number of parts that are then integrated separately. Many methods are known that split the right-hand side into two parts. This approach is limiting, however, and there are situations when 3-splitting is more natural and ultimately more advantageous. The second-order Strang operator-splitting method readily generalizes to a right-hand side splitting into any number of operators. It is arguably the most popular method for 3-splitting because of its efficiency, ease of implementation, and intuitive nature. Other 3-splitting methods exist, but they are less well-known, and \rev{analysis and} evaluation of their performance in practice are scarce. We demonstrate the effectiveness of some alternative 3-split, second-order methods to Strang splitting on two problems: the reaction-diffusion Brusselator, which can be split into three parts that each have closed-form solutions, and the kinetic Vlasov--Poisson equations that is used in semi-Lagrangian plasma simulations. We find alternative second-order 3-operator-splitting methods that realize efficiency gains of 10\%--20\% over traditional Strang splitting. Our analysis for the practical assessment of efficiency of operator-splitting methods includes the computational cost of the integrators and can be used in method design.

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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