On k-folding map-germs and hidden symmetries of surfaces in the Euclidean 3-space

G. Peñafort Sanchis, F. Tari

Let $M$ be a smooth surface in ${\mathbb{R}}^3$ (or a complex surface in ${\mathbb{C}}^3$) and $k\ge 2$ be an integer. At any point on $M$ and for any plane in ${\mathbb{R}}^3$, we constru…