Stochastic parareal : an application of probabilistic methods to time-parallelization

[thumbnail of WRAP-stochastic-parareal-application-probabilistic-methods-time-parallelization-2023.pdf]
Preview
PDF
WRAP-stochastic-parareal-application-probabilistic-methods-time-parallelization-2023.pdf - Accepted Version - Requires a PDF viewer.
Available under License Creative Commons Attribution 4.0.

Download (2MB) | Preview

Request Changes to record.

Abstract

Parareal is a well-studied algorithm for numerically integrating systems of time-dependent differential equations by parallelizing the temporal domain. Given approximate initial values at each temporal subinterval, the algorithm locates a solution in a fixed number of iterations using a predictor-corrector, stopping once a tolerance is met. This iterative process combines solutions located by inexpensive (coarse resolution) and expensive (fine resolution) numerical integrators. In this paper, we introduce a stochastic parareal algorithm aimed at accelerating the convergence of the deterministic parareal algorithm. Instead of providing the predictor-corrector with a deterministically located set of initial values, the stochastic algorithm samples initial values from dynamically varying probability distributions in each temporal subinterval. All samples are then propagated in parallel using the expensive integrator. The set of sampled initial values yielding the most continuous (smoothest) trajectory across consecutive subintervals are fed into the predictor-corrector, converging in fewer iterations than the deterministic algorithm with a given probability. The performance of the stochastic algorithm, implemented using various probability distributions, is illustrated on low-dimensional systems of ordinary differential equations (ODEs). We provide numerical evidence that when the number of sampled initial values is large enough, stochastic parareal converges almost certainly in fewer iterations than the deterministic algorithm, maintaining solution accuracy. Given its stochastic nature, we also highlight that multiple simulations of stochastic parareal return a distribution of solutions that can represent a measure of uncertainty over the ODE solution.

Item Type: Journal Article
Subjects: Q Science > QA Mathematics > QA76 Electronic computers. Computer science. Computer software
Divisions: Faculty of Science, Engineering and Medicine > Science > Mathematics
Faculty of Science, Engineering and Medicine > Science > Statistics
SWORD Depositor: Library Publications Router
Library of Congress Subject Headings (LCSH): Parallel algorithms, Parallel processing (Electronic computers), Differential equations -- Numerical solutions -- Data processing, Machine learning -- Mathematics, Computer algorithms
Journal or Publication Title: SIAM Journal on Scientific Computing
Publisher: Society for Industrial and Applied Mathematics
ISSN: 1064-8275
Official Date: 7 July 2022
Dates:
Date
Event
7 July 2022
Published
30 March 2022
Accepted
Page Range: S82-S102
DOI: 10.1137/21m1414231
Status: Peer Reviewed
Publication Status: Published
Access rights to Published version: Restricted or Subscription Access
Date of first compliant deposit: 22 June 2023
Date of first compliant Open Access: 22 June 2023
RIOXX Funder/Project Grant:
Project/Grant ID
RIOXX Funder Name
Funder ID
633053
Euratom Research and Training Programme
UNSPECIFIED
EP/S022244/1
[EPSRC] Engineering and Physical Sciences Research Council
Open Access Version:
URI: https://wrap.warwick.ac.uk/167539/

Export / Share Citation


Request changes or add full text files to a record

Repository staff actions (login required)

View Item View Item