On Lagrangians with Reduced-Order Euler-Lagrange Equations

If a Lagrangian defining a variational problem has order k, then its Euler-Lagrange equations generically have order 2k. This paper considers the case where the Euler-Lagrange equations have order strictly less than 2k, and shows that in such a case the Lagrangian must be a polynomial in the highest...

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Published in:Symmetry, Integrability and Geometry: Methods and Applications
Date:2018
Main Author: Saunders, D.
Format: Article
Language:English
Published: Інститут математики НАН України 2018
Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/209761
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Journal Title:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Cite this:On Lagrangians with Reduced-Order Euler-Lagrange Equations / D. Saunders // Symmetry, Integrability and Geometry: Methods and Applications. — 2018. — Т. 14. — Бібліогр.: 9 назв. — англ.

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Digital Library of Periodicals of National Academy of Sciences of Ukraine
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author Saunders, D.
author_facet Saunders, D.
citation_txt On Lagrangians with Reduced-Order Euler-Lagrange Equations / D. Saunders // Symmetry, Integrability and Geometry: Methods and Applications. — 2018. — Т. 14. — Бібліогр.: 9 назв. — англ.
collection DSpace DC
container_title Symmetry, Integrability and Geometry: Methods and Applications
description If a Lagrangian defining a variational problem has order k, then its Euler-Lagrange equations generically have order 2k. This paper considers the case where the Euler-Lagrange equations have order strictly less than 2k, and shows that in such a case the Lagrangian must be a polynomial in the highest-order derivative variables, with a specific upper bound on the degree of the polynomial. The paper also provides an explicit formulation, derived from a geometrical construction, of a family of such k-th order Lagrangians, and it is conjectured that all such Lagrangians arise in this way.
first_indexed 2025-12-07T18:46:52Z
format Article
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institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 1815-0659
language English
last_indexed 2025-12-07T18:46:52Z
publishDate 2018
publisher Інститут математики НАН України
record_format dspace
spelling Saunders, D.
2025-11-26T11:22:56Z
2018
On Lagrangians with Reduced-Order Euler-Lagrange Equations / D. Saunders // Symmetry, Integrability and Geometry: Methods and Applications. — 2018. — Т. 14. — Бібліогр.: 9 назв. — англ.
1815-0659
2010 Mathematics Subject Classification: 58E30
arXiv: 1801.06888
https://nasplib.isofts.kiev.ua/handle/123456789/209761
https://doi.org/10.3842/SIGMA.2018.089
If a Lagrangian defining a variational problem has order k, then its Euler-Lagrange equations generically have order 2k. This paper considers the case where the Euler-Lagrange equations have order strictly less than 2k, and shows that in such a case the Lagrangian must be a polynomial in the highest-order derivative variables, with a specific upper bound on the degree of the polynomial. The paper also provides an explicit formulation, derived from a geometrical construction, of a family of such k-th order Lagrangians, and it is conjectured that all such Lagrangians arise in this way.
The author would like to thank the referees for their helpful suggestions regarding the presentation of some technical aspects of this work.
en
Інститут математики НАН України
Symmetry, Integrability and Geometry: Methods and Applications
On Lagrangians with Reduced-Order Euler-Lagrange Equations
Article
published earlier
spellingShingle On Lagrangians with Reduced-Order Euler-Lagrange Equations
Saunders, D.
title On Lagrangians with Reduced-Order Euler-Lagrange Equations
title_full On Lagrangians with Reduced-Order Euler-Lagrange Equations
title_fullStr On Lagrangians with Reduced-Order Euler-Lagrange Equations
title_full_unstemmed On Lagrangians with Reduced-Order Euler-Lagrange Equations
title_short On Lagrangians with Reduced-Order Euler-Lagrange Equations
title_sort on lagrangians with reduced-order euler-lagrange equations
url https://nasplib.isofts.kiev.ua/handle/123456789/209761
work_keys_str_mv AT saundersd onlagrangianswithreducedordereulerlagrangeequations