Zobrazeno 1 - 10
of 36
pro vyhledávání: '"Mohammed Guediri"'
Autor:
Sharief Deshmukh, Mohammed Guediri
Publikováno v:
AIMS Mathematics, Vol 9, Iss 10, Pp 28765-28777 (2024)
Given a conformal vector field $ X $ defined on an $ n $-dimensional Riemannian manifold $ \left(N^{n}, g\right) $, naturally associated to $ X $ are the conformal factor $ \sigma $, a smooth function defined on $ N^{n} $, and a skew symmetric $ (1,
Externí odkaz:
https://doaj.org/article/e3857dab401147d583b71c244491036f
Autor:
Mohammed Guediri, Sharief Deshmukh
Publikováno v:
AIMS Mathematics, Vol 9, Iss 1, Pp 1899-1910 (2024)
An odd-dimensional sphere admits a killing vector field, induced by the transform of the unit normal by the complex structure of the ambiant Euclidean space. In this paper, we studied orientable hypersurfaces in a Euclidean space that admits a unit K
Externí odkaz:
https://doaj.org/article/812e59684d8a4e35845f4cf8e14eea0d
Autor:
Norah Alshehri, Mohammed Guediri
Publikováno v:
Mathematics, Vol 12, Iss 18, p 2914 (2024)
This paper explores the properties of projective vector fields on semi-Riemannian manifolds. The main result establishes that if a projective vector field P on such a manifold is also a conformal vector field with potential function ψ and the vector
Externí odkaz:
https://doaj.org/article/3a68c70df82d4b0393e8a0475dc2e03e
Autor:
Norah Alessa, Mohammed Guediri
Publikováno v:
Axioms, Vol 13, Iss 9, p 636 (2024)
This paper investigates generalized Robertson–Walker (GRW) spacetimes by analyzing Riemannian hypersurfaces within pseudo-Riemannian warped product manifolds of the form (M¯,g¯), where M¯=R×fM and g¯=ϵdt2+f2(t)gM. We focus on the scalar curva
Externí odkaz:
https://doaj.org/article/28828ed848084e548d6ca0206a274b24
Autor:
Norah Alshehri, Mohammed Guediri
Publikováno v:
Symmetry, Vol 16, Iss 5, p 601 (2024)
In this paper, we investigate Ricci solitons on spacelike hypersurfaces in a special Lorentzian warped product manifold, the so-called generalized Robertson–Walker (GRW) spacetimes. Such spacetimes admit a natural form of symmetry which is represen
Externí odkaz:
https://doaj.org/article/82287977affc4798b1da211a390ae2e8
Autor:
Norah Alshehri, Mohammed Guediri
Publikováno v:
Mathematics, Vol 12, Iss 6, p 842 (2024)
In this article, we investigate Ricci solitons occurring on spacelike hypersurfaces of Einstein Lorentzian manifolds. We give the necessary and sufficient conditions for a spacelike hypersurface of a Lorentzian manifold, equipped with a closed confor
Externí odkaz:
https://doaj.org/article/f81b3a52fb9742778ae8748948e55fa6
Autor:
Norah Alessa, Mohammed Guediri
Publikováno v:
Mathematics, Vol 11, Iss 20, p 4281 (2023)
We obtain some generalized Minkowski type integral formulas for compact Riemannian (resp., spacelike) hypersurfaces in Riemannian (resp., Lorentzian) manifolds in the presence of an arbitrary vector field that we assume to be timelike in the case whe
Externí odkaz:
https://doaj.org/article/d9c985752b374fc69fd86249ebfd04e3
Autor:
Sharief Deshmukh, Mohammed Guediri
Publikováno v:
AIMS Mathematics, Vol 6, Iss 7, Pp 7733-7740 (2021)
We use the tangential component $ \psi ^{T} $ of an immersion of a compact hypersurface of the Euclidean space $ \mathbf{E}^{m+1} $ in finding two characterizations of a sphere. In first characterization, we use $ \psi ^{T} $ as a geodesic vector fie
Externí odkaz:
https://doaj.org/article/df6a38cf86cf431c8787d8e1d1fd4f22
Autor:
Mohammed Guediri, Kholoud Albalawi
Publikováno v:
Arab Journal of Mathematical Sciences, Vol 24, Iss 1, Pp 101-124 (2018)
A left-symmetric algebra A is said to be a derivation algebra if all its left and right multiplications are derivations of the Lie algebra associated to A. In this paper, we shall study derivation algebras over R and then classify almost all those of
Externí odkaz:
https://doaj.org/article/99a2317e0fab48b9a88ebf5ed382f1dd
Autor:
Mohammed Guediri, Norah Alshehri
Publikováno v:
Arab Journal of Mathematical Sciences, Vol 23, Iss 1, Pp 74-84 (2017)
Let n≥3. We show that semi-symmetry and Ricci-semisymmetry conditions are equivalent for any n-dimensional Lorentzian hypersurface in a Lorentzian space form with nonzero curvature. We also show that these curvature conditions are equivalent for an
Externí odkaz:
https://doaj.org/article/2ba95302886c48a2abf9c2b6b30d3d80