Title
A Class of Multirate Infinitesimal GARK Methods
Abstract
Differential equations arising in many practical applications are characterized by multiple time scales. Multirate time integration seeks to solve them efficiently by discretizing each scale with a different, appropriate time step, while ensuring the overall accuracy and stability of the numerical solution. In a seminal paper, Knoth and Wolke [Appl. Numer. Math., 28 (1998), pp. 327-341] proposed a hybrid solution approach: discretize the slow component with an explicit Runge-Kutta method, and advance the fast component via a modified fast differential equation. The idea led to the development of multirate infinitesimal step (MIS) methods by Wensch, Knoth, and Galant [BIT, 49 (2009), pp. 449-473]. Gunther and Sandu [Numer. Math., 133 (2016), pp. 497-524] explained MIS schemes as a particular case of multirate General-structure Additive Runge-Kutta (MR-GARK) methods. The hybrid approach offers extreme flexibility in the choice of the numerical solution process for the fast component. This work constructs a family of multirate infinitesimal GARK schemes (MRI-GARK) that extends the hybrid dynamics approach in multiple ways. Order conditions theory and stability analyses are developed, and practical explicit and implicit methods of up to order four are constructed. Numerical results confirm the theoretical findings. We expect the new MRI-GARK family to be most useful for systems of equations with widely disparate time scales, where the fast process is dispersive, and where the influence of the fast component on the slow dynamics is weak.
Year
DOI
Venue
2019
10.1137/18M1205492
SIAM JOURNAL ON NUMERICAL ANALYSIS
Keywords
Field
DocType
multirate time integration,hybrid dynamics,general-structure additive Runge-Kutta methods
Differential equation,Discretization,Applied mathematics,Mathematical analysis,Infinitesimal,Mathematics
Journal
Volume
Issue
ISSN
57
5
0036-1429
Citations 
PageRank 
References 
0
0.34
3
Authors
1
Name
Order
Citations
PageRank
Adrian Sandu132558.93