Results 41 to 50 of about 32,038 (159)
On maximal hypersurfaces in Lorentz manifolds admitting a parallel lightlike vector field [PDF]
, 2016 We study constant mean curvature spacelike hypersurfaces and in particular maximal hypersurfaces immersed in pp-wave spacetimes satisfying the timelike convergence condition.
José A. S. Pelegrín +2 more
semanticscholar +1 more source
Journal of Function Spaces, Volume 2018, Issue 1, 2018., 2018 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 ...
Xue Song, Zhigang Wang, Gestur Ólafsson
wiley +1 more source
Journal of Function Spaces, Volume 2016, Issue 1, 2016., 2016 We consider one‐parameter null hypersurfaces associated with spacelike curves. The spacelike curves are in anti‐de Sitter 3‐space while one‐parameter null hypersurfaces lie in 4‐dimensional semi‐Euclidean space with index 2. We classify the generic singularities of the hypersurfaces, which are cuspidal edges and swallowtails.
Yongqiao Wang +3 more
wiley +1 more source
Advances in Mathematical Physics, Volume 2016, Issue 1, 2016., 2016 We discuss the physics of interacting fields and particles living in a de Sitter Lorentzian manifold (dSLM), a submanifold of a 5‐dimensional pseudo‐Euclidean (5dPE) equipped with a metric tensor inherited from the metric of the 5dPE space. The dSLM is naturally oriented and time oriented and is the arena used to study the energy‐momentum conservation ...
Waldyr A. Rodrigues +2 more
wiley +1 more source
Construction of Initial Data Sets for Lorentzian Manifolds with Lightlike Parallel Spinors [PDF]
, 2021 Lorentzian manifolds with parallel spinors are important objects of study in several branches of geometry, analysis and mathematical physics. Their Cauchy problem has recently been discussed by Baum, Leistner and Lischewski, who proved that the problem ...
Ammann, Bernd +2 more
core +1 more source
Lightlike shell solitons of extremal space-time film [PDF]
Journal of Physics Communications, 2015 New exact solution class of Born—Infeld type nonlinear scalar field model is obtained. The variational principle of this model has a specific form which is characteristic for extremal four-dimensional hypersurface or hyper-film in five-dimensional space ...
A. Chernitskii
semanticscholar +1 more source
An example of an almost hyperbolic Hermitian manifold
International Journal of Mathematics and Mathematical Sciences, 1998 The almost hyperbolic Hermitan manifolds introduced in [1] were classified for the first time in [2]. In this note we construct an example of an almost hyperbolic Hermitan manifold which belongs to a certain class that we study here.
Cornelia-Livia Bejan, Liviu Ornea
doaj +1 more source
Singularities of Null Hypersurfaces of Pseudonull Curves
Journal of Function Spaces, Volume 2015, Issue 1, 2015., 2015 The main goal of this paper is to study the singularities of null hypersurfaces of pseudonull curves. To do this we construct a null frame and a Lorentz distance‐squared function of the pseudonull curve. The relations are shown between singularities of the null hypersurfaces and those, of the Lorentz distance‐squared function.
Xiupeng Cui, Donghe Pei, Hugo Leiva
wiley +1 more source
A note on conformal connections on lightlike hypersurfaces [PDF]
Conformal Geometry and Dynamics of the American Mathematical Society, 2007 Degenerate submanifolds of pseudo-Riemannian manifolds are quite difficult to study because there is no preferred connection when the submanifold is not totally geodesic. For the particular case of degenerate totally umbilical hypersurfaces, we show that there are “Weyl” connections adapted to the induced structure on the hypersurface.
Atindogbe, Cyriaque +1 more
openaire +3 more sources
Time‐Dependent Evolving Null Horizons of a Dynamical Spacetime
International Scholarly Research Notices, Volume 2014, Issue 1, 2014., 2014 Totally geodesic null hypersurfaces have been widely used in the study of isolated black holes. In this paper, we introduce a new quasilocal notion of a family of totally umbilical null hypersurfaces called evolving null horizons (ENH) of a dynamical spacetime, satisfied under an appropriate energy condition.
K. L. Duggal +2 more
wiley +1 more source