English

A one-dimensional variational problem with continuous Lagrangian and singular minimizer

Classical Analysis and ODEs 2015-05-18 v2

Abstract

We construct a continuous Lagrangian, strictly convex and superlinear in the third variable, such that the associated variational problem has a Lipschitz minimizer which is non-differentiable on a dense set. More precisely, the upper and lower Dini derivatives of the minimizer differ by a constant on a dense (hence second category) set. In particular, we show that mere continuity is an insufficient smoothness assumption for Tonelli's partial regularity theorem.

Keywords

Cite

@article{arxiv.1002.3070,
  title  = {A one-dimensional variational problem with continuous Lagrangian and singular minimizer},
  author = {Richard Gratwick and David Preiss},
  journal= {arXiv preprint arXiv:1002.3070},
  year   = {2015}
}

Comments

27 pages, second author added, introductory material changed, minor typos corrected, some cross-references re-formatted, some references added

R2 v1 2026-06-21T14:47:29.781Z