Partial regularity of minimizers for real-analytic sub-Riemannian metrics

Abstract

In the real-analytic setting, we show that all sub-Riemannian minimizers (parametrized by the arc-length) are real-analytic everywhere except an at most countable non-dense set. In particular, non-analyticity may occur only on a set of measure zero of the domain of definition of a sub-Riemannian minimizer. Furthermore, we provide a geometrical condition which implies the absence of the so called strictly abnormal minimizers. In particular, under such condition, all sub-Riemannian minimizers (parametrized by the arc-length) are real-analytic.