Arcs, balls and spheres that cannot be attractors in ${\mathbb{R}}^3$

J. J. Sánchez-Gabites

For any compact set $K\subseteq {\mathbb{R}}^3$ we define a number $r(K)$ that is either a nonnegative integer or $\infty$. Intuitively, $r(K)$ provides some information on how wild…