Výsledky vyhledávání - "Kashani, S. M. B."

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Geodesic completeness of some Lorentzian simple Lie groups

Autor: Ebrahimi, E., Kashani, S. M. B., Vanaei, M. J.

In this paper we investigate geodesic completeness of left-invariant Lorentzian metrics on a simple Lie group $G$ when there exists a left-invariant Killing vector field $Z$ on $G$. Among other results, it is proved that if $Z$ is timelike, or $G$ is

Externí odkaz: http://arxiv.org/abs/2008.00543

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Semi-Riemannian hypersurfaces in $\mathbb{L}^{n+1}$ with a totally geodesic foliation of codimension one

Autor: Kashani, S. M. B., Vanaei, M. J., Yaghoobi, S. M.

We classify hypersurfaces of the Minkowski space $\L^{n+1}$ that carry a totally geodesic foliation with complete leaves of codimension one. We prove that such a hypersurface is ruled, or a partial tube over a curve or contains a two or three dimensi

Externí odkaz: http://arxiv.org/abs/1810.06016

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Real hypersurfaces in $Q^m$ with commuting structure Jacobi operator

Autor: Heidari, N., Kashani, S. M. B., Vanaei, M. J.

In this paper we study real hypersurfaces in the complex quadric space $Q^m$ whose structure Jacobi operator commutes with their structure tensor field. We show that the Reeb curvature $\alpha$ of such hypersurfaces is constant and if $\alpha$ is non

Externí odkaz: http://arxiv.org/abs/1807.11021

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Cohomogeneity one actions on anti de Sitter spacetimes

Autor: Diaz-Ramos, J. C., Kashani, S. M. B., Vanaei, M. J.

In this paper we classify, up to orbit equivalence, cohomogeneity one actions of connected closed Lie subgroups of $U(1,n)$ on the $(2n+1)$-dimensional anti de Sitter spacetime $AdS^{2n+1}$. We also give some new examples of nonproper cohomogeneity o

Externí odkaz: http://arxiv.org/abs/1609.05644

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Hypersurfaces in space forms satisfying the condition $L_kx=Ax+b$

Autor: Alias, Luis J., Kashani, S. M. B.

We study hypersurfaces either in the sphere \s{n+1} or in the hyperbolic space \h{n+1} whose position vector $x$ satisfies the condition $L_kx=Ax+b$, where $L_k$ is the linearized operator of the $(k+1)$-th mean curvature of the hypersurface for a fi

Externí odkaz: http://arxiv.org/abs/0908.3595

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