Behavior of corank one singular points on wave fronts

Kentaro Saji, Masaaki Umehara, Kotaro Yamada

Let $M^2$ be an oriented 2-manifold and $f:M^2\to R^3$ a $C^{\infty }$-map. A point $p\in M^2$ is called a singular point if $f$ is not an immersion at $p$. The map $f$ is called a fr…