The agenda of next meetings of Krasil'shchik's seminar on geometry of
differential equations at the Independent University of Moscow.

On 8 April seminar will be held online only.

Speaker: Wijnand Steneker
Title: On globally invariant Euler-Lagrange equations for curves
Language: English
Zoom:
8817121842?
Zoom Passcode: 0804

Abstract:

Invariant Lagrangians yield invariant Euler-Lagrange equations and local
methods for computing these are well-established, starting with Anderson
and Griffiths. We focus on global algebraic invariants, using an
invariant version of variational bicomplex or, more generally,
C-spectral sequence. One motivation is the question, posed by Kogan and
Olver, whether invariant variational problems with only singular
extremals can exist. We show that the example of conformal geodesics
answers this question positively and motivates the need for global
invariant methods. We then discuss how to compute invariant
Euler-Lagrange equations using global invariants and how this can be
applied in practice, both as a supplementary tool for existing local
methods, as well as in a purely global setting. We demonstrate these
principles with some examples, all for systems of ODEs (unparametrized
curves).

This talk is based on joint work with Boris Kruglikov and Eivind
Schneider (Troms?).

arxiv 2601.06985


The seminar meets on Wednesday evenings at 19:20 MSK in Zoom,
Meeting ID: 88 17 12 1842
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FROM 202.120.11.*