13 papers · 1 filter
Focal surfaces of fronts associated to unbounded principal curvatures
Keisuke Teramoto
We study focal surfaces of (wave) fronts associated to unbounded principal curvatures near non-degenerate singular points of initial fronts. We give characterizations of singularit…
Geometry of lightlike locus on mixed type surfaces in Lorentz-Minkowski 3-space from a contact viewpoint
Atsufumi Honda, Shyuichi Izumiya, Kentaro Saji +1
A surface in the Lorentz-Minkowski -space is generally a mixed type surface, namely, it has the lightlike locus. We study local differential geometric properties of such a locus…
On Gaussian curvatures and singularities of Gauss maps of cuspidal edges
Keisuke Teramoto
We show relation between sign of Gaussian curvature of cuspidal edge and geometric invariants through types of singularities of Gauss map. Moreover, we define and characterize posi…
Geometric properties near singular points of surfaces given by certain representation formulae
Yoshiki Matsushita, Takuya Nakashima, Keisuke Teramoto
We investigate geometric properties of surfaces given by certain formulae. In particular, we calculate the singular curvature and the limiting normal curvature of such surfaces alo…
Behavior of principal curvatures of frontals near non-front singular points and their application
Kentaro Saji, Keisuke Teramoto
We investigate behavior of principal curvatures and principal vectors near a non-degenerate singular point of the first kind of frontals. As an application, we extend the notion of…
Surfaces of revolution of frontals in the Euclidean space
Masatomo Takahashi, Keisuke Teramoto
For Legendre curves, we consider surfaces of revolution of frontals. The surface of revolution of a frontal can be considered as a framed base surface. We give the curvatures and b…