On a class of special Euler-Lagrange equations

Baisheng Yan

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arXiv · 2212.12481

On a class of special Euler-Lagrange equations

Baisheng Yan

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Abstract

We make some remarks on the Euler-Lagrange equation of energy functional $I(u)=\int_\Omega f(\det Du)\,dx,$ where $f\in C^1(\mathbb R).$ For certain weak solutions $u$ we show that the function $f'(\det Du)$ must be a constant over the domain $\Omega$ and thus, when $f$ is convex, all such solutions are an energy minimizer of $I(u).$ However, other weak solutions exist such that $f'(\det Du)$ is not constant on $\Omega.$ We also prove some results concerning the homeomorphism solutions, non-quasimonotonicty, radial solutions, and some special properties and questions in the 2-D cases.

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Baisheng Yan. 2022-12-23. On a class of special Euler-Lagrange equations. https://arxiv.org/abs/2212.12481

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