A Note on Umbilic Points at Infinity

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autor principal: Guilfoyle, Brendan
Formato: Preprint
Publicado: 2021
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866911871800442880
author Guilfoyle, Brendan
author_facet Guilfoyle, Brendan
contents In this note a definition of umbilic point at infinity is proposed, at least for surfaces that are homogeneous polynomial graphs over a plane in Euclidean 3-space. This is a stronger definition than that of Toponogov in his study of complete convex surfaces, and allows one to distinguish between different umbilic points at infinity. It is proven that all such umbilic points at infinity are isolated, that they occur in pairs and are the zeroes of the projective extension of the third fundamental form, as developed by the authors in a previous paper. A geometric interpretation for our definition is that an umbilic point at infinity occurs when the tangent to the level set at infinity is also an asymptotic direction at infinity. We prove that a homogeneous polynomial graph must have an umbilic point, albeit at infinity.
format Preprint
id arxiv_https___arxiv_org_abs_2108_09842
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle A Note on Umbilic Points at Infinity
Guilfoyle, Brendan
Differential Geometry
53C12, 53A05, 34K32, 53A20
In this note a definition of umbilic point at infinity is proposed, at least for surfaces that are homogeneous polynomial graphs over a plane in Euclidean 3-space. This is a stronger definition than that of Toponogov in his study of complete convex surfaces, and allows one to distinguish between different umbilic points at infinity. It is proven that all such umbilic points at infinity are isolated, that they occur in pairs and are the zeroes of the projective extension of the third fundamental form, as developed by the authors in a previous paper. A geometric interpretation for our definition is that an umbilic point at infinity occurs when the tangent to the level set at infinity is also an asymptotic direction at infinity. We prove that a homogeneous polynomial graph must have an umbilic point, albeit at infinity.
title A Note on Umbilic Points at Infinity
topic Differential Geometry
53C12, 53A05, 34K32, 53A20
url https://arxiv.org/abs/2108.09842