2 problems

Let $\mathbb{G}$ be a Carnot group with left-invariant sub-Riemannian structure. A curve $\gamma(t):\mathbb{R}\to\mathbb{G}$ is a metric line if it is a globally minimizing sub-Rie…

Let ${\mathbb G}$ be a Carnot group and let $W$ be a horizontal half-space. Denote by $S_W$ the semigroup generated by $W$, by $\bar S_W$ its closure, by $\mathfrak w_{\bar S_W}$ t…