Singularities of Indefinite Hypersurfaces and Indefinite Surfaces along Timelike Curves in Nullcone with Index Two

In this paper, a class of indefinite hypersurfaces and a class of indefinite surfaces generated by timelike curves located in nullcone in 4-dimensional semi-Euclidean space with index 2 are discussed. Using the unfolding theory in singularity theory, the singularities of the indefinite hypersurfaces...

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Main Authors: Xue Song, Zhigang Wang
Format: Article
Language:English
Published: Wiley 2018-01-01
Series:Journal of Function Spaces
Online Access:http://dx.doi.org/10.1155/2018/5859410
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author Xue Song
Zhigang Wang
author_facet Xue Song
Zhigang Wang
author_sort Xue Song
collection DOAJ
description In this paper, a class of indefinite hypersurfaces and a class of indefinite surfaces generated by timelike curves located in nullcone in 4-dimensional semi-Euclidean space with index 2 are discussed. Using the unfolding theory in singularity theory, the singularities of the indefinite hypersurfaces and the indefinite surfaces are classified and the different kinds of singularities are estimated by means of a geometric invariant σ. Meanwhile, the definition of osculating nullcone is presented; the study shows that the differential geometric invariant σ of timelike curves measured also the order of the contact between a timelike curve and a osculating nullcone ONCv0⁎. Finally, some relevant counterexamples are indicated.
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institution Kabale University
issn 2314-8896
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language English
publishDate 2018-01-01
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series Journal of Function Spaces
spelling doaj-art-014ec91f1cce42da8bf4e6d69ec8834d2025-08-20T03:55:24ZengWileyJournal of Function Spaces2314-88962314-88882018-01-01201810.1155/2018/58594105859410Singularities of Indefinite Hypersurfaces and Indefinite Surfaces along Timelike Curves in Nullcone with Index TwoXue Song0Zhigang Wang1School of Mathematical Sciences, Harbin Normal University, Harbin 150025, ChinaSchool of Mathematical Sciences, Harbin Normal University, Harbin 150025, ChinaIn this paper, a class of indefinite hypersurfaces and a class of indefinite surfaces generated by timelike curves located in nullcone in 4-dimensional semi-Euclidean space with index 2 are discussed. Using the unfolding theory in singularity theory, the singularities of the indefinite hypersurfaces and the indefinite surfaces are classified and the different kinds of singularities are estimated by means of a geometric invariant σ. Meanwhile, the definition of osculating nullcone is presented; the study shows that the differential geometric invariant σ of timelike curves measured also the order of the contact between a timelike curve and a osculating nullcone ONCv0⁎. Finally, some relevant counterexamples are indicated.http://dx.doi.org/10.1155/2018/5859410
spellingShingle Xue Song
Zhigang Wang
Singularities of Indefinite Hypersurfaces and Indefinite Surfaces along Timelike Curves in Nullcone with Index Two
Journal of Function Spaces
title Singularities of Indefinite Hypersurfaces and Indefinite Surfaces along Timelike Curves in Nullcone with Index Two
title_full Singularities of Indefinite Hypersurfaces and Indefinite Surfaces along Timelike Curves in Nullcone with Index Two
title_fullStr Singularities of Indefinite Hypersurfaces and Indefinite Surfaces along Timelike Curves in Nullcone with Index Two
title_full_unstemmed Singularities of Indefinite Hypersurfaces and Indefinite Surfaces along Timelike Curves in Nullcone with Index Two
title_short Singularities of Indefinite Hypersurfaces and Indefinite Surfaces along Timelike Curves in Nullcone with Index Two
title_sort singularities of indefinite hypersurfaces and indefinite surfaces along timelike curves in nullcone with index two
url http://dx.doi.org/10.1155/2018/5859410
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AT zhigangwang singularitiesofindefinitehypersurfacesandindefinitesurfacesalongtimelikecurvesinnullconewithindextwo