Lepage Equivalents and the Variational Bicomplex

We show how to construct, for a Lagrangian of arbitrary order, a Lepage equivalent satisfying the closure property: that the Lepage equivalent vanishes precisely when the Lagrangian is null. The construction uses a homotopy operator for the horizontal differential of the variational bicomplex. A cho...

Full description

Saved in:
Bibliographic Details
Published in:Symmetry, Integrability and Geometry: Methods and Applications
Date:2024
Main Author: Saunders, David
Format: Article
Language:English
Published: Інститут математики НАН України 2024
Online Access:https://nasplib.isofts.kiev.ua/handle/123456789/212110
Tags: Add Tag
No Tags, Be the first to tag this record!
Journal Title:Digital Library of Periodicals of National Academy of Sciences of Ukraine
Cite this:Lepage Equivalents and the Variational Bicomplex. David Saunders. SIGMA 20 (2024), 013, 18 pages

Institution

Digital Library of Periodicals of National Academy of Sciences of Ukraine
_version_ 1862706400569851904
author Saunders, David
author_facet Saunders, David
citation_txt Lepage Equivalents and the Variational Bicomplex. David Saunders. SIGMA 20 (2024), 013, 18 pages
collection DSpace DC
container_title Symmetry, Integrability and Geometry: Methods and Applications
description We show how to construct, for a Lagrangian of arbitrary order, a Lepage equivalent satisfying the closure property: that the Lepage equivalent vanishes precisely when the Lagrangian is null. The construction uses a homotopy operator for the horizontal differential of the variational bicomplex. A choice of symmetric linear connection on the manifold of independent variables, and a global homotopy operator constructed using that connection, may then be used to extend any global Lepage equivalent to one satisfying the closure property. In the second part of the paper, we investigate the rôle of vertical endomorphisms in constructing such Lepage equivalents. These endomorphisms may be used directly to construct local homotopy operators. Together with a symmetric linear connection, they may also be used to construct global vertical tensors, and these define infinitesimal nonholonomic projections, which in turn may be used to construct Lepage equivalents. We conjecture that these global vertical tensors may also be used to define global homotopy operators.
first_indexed 2026-03-19T00:30:45Z
format Article
fulltext
id nasplib_isofts_kiev_ua-123456789-212110
institution Digital Library of Periodicals of National Academy of Sciences of Ukraine
issn 1815-0659
language English
last_indexed 2026-03-19T00:30:45Z
publishDate 2024
publisher Інститут математики НАН України
record_format dspace
spelling Saunders, David
2026-01-28T13:56:30Z
2024
Lepage Equivalents and the Variational Bicomplex. David Saunders. SIGMA 20 (2024), 013, 18 pages
1815-0659
2020 Mathematics Subject Classification: 58A10; 58A20; 83D05
arXiv:2309.01594
https://nasplib.isofts.kiev.ua/handle/123456789/212110
https://doi.org/10.3842/SIGMA.2024.013
We show how to construct, for a Lagrangian of arbitrary order, a Lepage equivalent satisfying the closure property: that the Lepage equivalent vanishes precisely when the Lagrangian is null. The construction uses a homotopy operator for the horizontal differential of the variational bicomplex. A choice of symmetric linear connection on the manifold of independent variables, and a global homotopy operator constructed using that connection, may then be used to extend any global Lepage equivalent to one satisfying the closure property. In the second part of the paper, we investigate the rôle of vertical endomorphisms in constructing such Lepage equivalents. These endomorphisms may be used directly to construct local homotopy operators. Together with a symmetric linear connection, they may also be used to construct global vertical tensors, and these define infinitesimal nonholonomic projections, which in turn may be used to construct Lepage equivalents. We conjecture that these global vertical tensors may also be used to define global homotopy operators.
I should like to acknowledge correspondence with Nicoleta Voicu, which encouraged me to return to this topic after several years. Some results from this paper were presented at a meeting in Torino in honour of Marco Ferraris in June 2023, and at the International Summer School on Global Analysis and Applications in Prešov in August 2023.
en
Інститут математики НАН України
Symmetry, Integrability and Geometry: Methods and Applications
Lepage Equivalents and the Variational Bicomplex
Article
published earlier
spellingShingle Lepage Equivalents and the Variational Bicomplex
Saunders, David
title Lepage Equivalents and the Variational Bicomplex
title_full Lepage Equivalents and the Variational Bicomplex
title_fullStr Lepage Equivalents and the Variational Bicomplex
title_full_unstemmed Lepage Equivalents and the Variational Bicomplex
title_short Lepage Equivalents and the Variational Bicomplex
title_sort lepage equivalents and the variational bicomplex
url https://nasplib.isofts.kiev.ua/handle/123456789/212110
work_keys_str_mv AT saundersdavid lepageequivalentsandthevariationalbicomplex