RT Journal Article T1 Arcs, balls and spheres that cannot be attractors in R^3 A1 Sánchez Gabites, Jaime Jorge AB For any compact set K ⊆ R3 we define a number r(K) that is either a nonnegative integer or ∞. Intuitively, r(K) provides some information on how wildly K sits in R3. We show that attractors for discrete or continuous dynamical systems have finite r and then prove that certain arcs, balls and spheres cannot be attractors by showing that their r is infinite. PB American Mathematical Society YR 2016 FD 2016 LK https://hdl.handle.net/20.500.14352/133268 UL https://hdl.handle.net/20.500.14352/133268 LA eng NO Ministerio de Ciencia e Innovación DS Docta Complutense RD 21 mar 2026