Results 51 to 60 of about 2,119 (92)

On the Conformal Geometry of Transverse Riemann-Lorentz Manifolds [PDF]

, 2006
Physical reasons suggested in \cite{Ha-Ha} for the \emph{Quantum Gravity Problem} lead us to study \emph{type-changing metrics} on a manifold. The most interesting cases are \emph{Transverse Riemann-Lorentz Manifolds}. Here we study the conformal geometry of such manifolds.
arxiv   +1 more source

Symmetries of f−associated standard static spacetimes and applications

Journal of the Egyptian Mathematical Society, 2017
The purpose of this note is to study and explore some collineation vector fields on standard static spacetimes If × M(also called f− associated SSST). Conformal vector fields, Ricci and matter collineations are studied.
H.K. El-Sayied, Sameh Shenawy, Noha Syied   +2 more
doaj  

A note on Rakić duality principle for Osserman manifolds [PDF]

arXiv, 2012
In this note we prove that for a Riemannian manifold the Osserman pointwise condition is equivalent to the Raki\'c duality principle.
arxiv  

Parallel spinors and holonomy groups on pseudo-Riemannian spinmanifolds [PDF]

arXiv, 1998
We describe the possible holonomy groups of simply connected irreducible non-locally symmetric pseudo-Riemannian spin manifolds which admit parallel spinors.
arxiv  

Lorentzian twistor spinors and CR-geometry [PDF]

arXiv, 1998
We prove that there exist global solutions of the twistor equation on the Fefferman spaces of strictly pseudoconvex spin manifolds of arbitrary dimension and we study their properties.
arxiv  

Skewadjoint operators on pseudoeuclidean spaces [PDF]

arXiv, 2003
We give a complete classification in canonical forms on finite-dimensional vector spaces over the real numbers.
arxiv  

Null Distance and Convergence of Lorentzian Length Spaces. [PDF]

Ann Henri Poincare, 2022
Kunzinger M, Steinbauer R.
europepmc   +1 more source

DUAL TIMELIKE NORMAL AND DUAL TIMELIKE SPHERICAL CURVES IN DUAL MINKOWSKI SPACE

Süleyman Demirel Üniversitesi Fen-Edebiyat Fakültesi Fen Dergisi, 2009
: In this paper, we give characterizations of dual timelike normal and dual timelike spherical curves in the dual Minkowski 3-space and we show that every dual timelike normal curve is also a dual timelike spherical curve.
Mehmet ÖNDER
doaj  

Feuilletages totalement geodesiques, flots riemanniens et varietes de Seifert [PDF]

arXiv, 2004
We study totally geodesic codimension 1 smooth foliations on Lorentzian manifold. We are in particular interested by the relations between riemannian flows and geodesic foliations. We prove that, up to a 2-cover, any Seifert bundle admit such a foliation.
arxiv  

A note on the Gannon-Lee theorem. [PDF]

Lett Math Phys, 2021
Schinnerl B, Steinbauer R.
europepmc   +1 more source