A. Braz, L.G.S. Duarte, H.S. Ferreira, A.C.S. Guabiraba, L.A.C.P. da Mota, I.S.S. Nascimento
{"title":"A new way to use nonlocal symmetries to determine first integrals of second-order nonlinear ordinary differential equations","authors":"A. Braz, L.G.S. Duarte, H.S. Ferreira, A.C.S. Guabiraba, L.A.C.P. da Mota, I.S.S. Nascimento","doi":"10.1016/j.cpc.2024.109426","DOIUrl":null,"url":null,"abstract":"<div><div>Finding first integrals of second-order nonlinear ordinary differential equations (nonlinear 2ODEs) is a very difficult task. In very complicated cases, where we cannot find Darboux polynomials (to construct an integrating factor) or a Lie symmetry (that allows us to simplify the equations), we sometimes can solve the problem by using a nonlocal symmetry. In <span><span>[1]</span></span>, <span><span>[2]</span></span>, <span><span>[3]</span></span> we developed (and improved) a method (S-function method) that is successful in finding nonlocal Lie symmetries to a large class of nonlinear rational 2ODEs. However, even with the nonlocal symmetry, we still need to solve a 1ODE (which can be very difficult to solve) to find the first integral. In this work we present a novel way of using the nonlocal symmetry to compute the first integral with a very efficient linear procedure.</div></div><div><h3>New version program summary</h3><div><em>Program Title: InSyDE</em> – Invariants and Symmetries of (rational second order ordinary) Differential Equations.</div><div><em>CPC Library link to program files:</em> <span><span>https://doi.org/10.17632/4ytft6zgk7.3</span><svg><path></path></svg></span></div><div><em>Licensing provisions:</em> CC by NC 3.0</div><div><em>Programming language:</em> Maple</div><div><em>Supplementary material:</em> Theoretical results and revision of the S-function method.</div><div><em>Journal reference of previous version:</em> Comput. Phys. Comm. Volume 234, January 2019, Pages 302-314 - <span><span>https://doi.org/10.1016/j.cpc.2018.05.009</span><svg><path></path></svg></span></div><div><em>Does the new version supersede the previous version?:</em> Yes.</div><div><em>Nature of problem:</em> Determining first integrals of rational second order ordinary differential equations.</div><div><em>Solution method:</em> The method is explained in the Summary of revisions and Supplementary material.</div><div><em>Reasons for the new version:</em> The <em>InSyDE</em> package after determining the S-function still needs to solve a first-order ordinary differential equation (1ODE) associated with the nonlocal symmetry (the so-called associated 1ODE – see <span><span>[2]</span></span>). The problem is that, for very complicated 1ODEs, this may not be practically feasible. We have developed an new and more efficient method that uses the nonlocal symmetry to (for a large class of 1ODEs) determine the first integral in a linear way.</div><div><em>Summary of revisions:</em> In order to implement the new method just mentioned above we have made modifications to the command (<span>Sfunction</span>) and introduced a new one: command (<span>Darlin</span>).</div></div>","PeriodicalId":285,"journal":{"name":"Computer Physics Communications","volume":"307 ","pages":"Article 109426"},"PeriodicalIF":7.2000,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computer Physics Communications","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0010465524003497","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS","Score":null,"Total":0}
引用次数: 0
Abstract
Finding first integrals of second-order nonlinear ordinary differential equations (nonlinear 2ODEs) is a very difficult task. In very complicated cases, where we cannot find Darboux polynomials (to construct an integrating factor) or a Lie symmetry (that allows us to simplify the equations), we sometimes can solve the problem by using a nonlocal symmetry. In [1], [2], [3] we developed (and improved) a method (S-function method) that is successful in finding nonlocal Lie symmetries to a large class of nonlinear rational 2ODEs. However, even with the nonlocal symmetry, we still need to solve a 1ODE (which can be very difficult to solve) to find the first integral. In this work we present a novel way of using the nonlocal symmetry to compute the first integral with a very efficient linear procedure.
New version program summary
Program Title: InSyDE – Invariants and Symmetries of (rational second order ordinary) Differential Equations.
CPC Library link to program files:https://doi.org/10.17632/4ytft6zgk7.3
Licensing provisions: CC by NC 3.0
Programming language: Maple
Supplementary material: Theoretical results and revision of the S-function method.
Journal reference of previous version: Comput. Phys. Comm. Volume 234, January 2019, Pages 302-314 - https://doi.org/10.1016/j.cpc.2018.05.009
Does the new version supersede the previous version?: Yes.
Nature of problem: Determining first integrals of rational second order ordinary differential equations.
Solution method: The method is explained in the Summary of revisions and Supplementary material.
Reasons for the new version: The InSyDE package after determining the S-function still needs to solve a first-order ordinary differential equation (1ODE) associated with the nonlocal symmetry (the so-called associated 1ODE – see [2]). The problem is that, for very complicated 1ODEs, this may not be practically feasible. We have developed an new and more efficient method that uses the nonlocal symmetry to (for a large class of 1ODEs) determine the first integral in a linear way.
Summary of revisions: In order to implement the new method just mentioned above we have made modifications to the command (Sfunction) and introduced a new one: command (Darlin).
期刊介绍:
The focus of CPC is on contemporary computational methods and techniques and their implementation, the effectiveness of which will normally be evidenced by the author(s) within the context of a substantive problem in physics. Within this setting CPC publishes two types of paper.
Computer Programs in Physics (CPiP)
These papers describe significant computer programs to be archived in the CPC Program Library which is held in the Mendeley Data repository. The submitted software must be covered by an approved open source licence. Papers and associated computer programs that address a problem of contemporary interest in physics that cannot be solved by current software are particularly encouraged.
Computational Physics Papers (CP)
These are research papers in, but are not limited to, the following themes across computational physics and related disciplines.
mathematical and numerical methods and algorithms;
computational models including those associated with the design, control and analysis of experiments; and
algebraic computation.
Each will normally include software implementation and performance details. The software implementation should, ideally, be available via GitHub, Zenodo or an institutional repository.In addition, research papers on the impact of advanced computer architecture and special purpose computers on computing in the physical sciences and software topics related to, and of importance in, the physical sciences may be considered.