2-semiarcs in $\mathrm{PG}(2,q)$, $q\le 13$

Daniele Bartoli, Giorgio Faina, György Kiss +2

A $2$-semiarc is a pointset ${\mathcal{S}}_k$ with the property that the number of tangent lines to ${\mathcal{S}}_k$ at each of its points is two. Using some theoretical results and…