Zobrazeno 1 - 10
of 147
pro vyhledávání: '"Sherif Abbas"'
We study the causal dynamics of an embedded null horizon foliated by marginally outer trapped surfaces (MOTS) for a locally rotationally symmetric background spacetime subjected to linear perturbations. We introduce a simple procedure which character
Externí odkaz:
http://arxiv.org/abs/2404.14742
We study the existence of gradient conformal Killing vectors (CKVs) in the class of locally rotationally symmetric (LRS) spacetimes which generalizes spherically symmetric spacetimes, and investigate some implications for the evolutionary character o
Externí odkaz:
http://arxiv.org/abs/2401.07605
Autor:
Sherif, Abbas M.
Publikováno v:
Gen Relativ Gravit 56, 15 (2024)
Let $M$ be a locally rotationally symmetric spacetime, and $\xi^a$ a conformal Killing vector for the metric on $M$, lying in the subspace spanned by the unit timelike direction and the preferred spatial direction, and with non-constant components. U
Externí odkaz:
http://arxiv.org/abs/2311.04682
Publikováno v:
J. High Energ. Phys. 2024, 28 (2024)
We investigate the charged Vaidya spacetime with conformal symmetry by classifying the horizons and finding its connection to Hawking temperature. We find a conformal Killing vector whose existence requires the mass and electric charge functions to b
Externí odkaz:
http://arxiv.org/abs/2309.17398
Publikováno v:
Eur. Phys. J. C 84, 69 (2024)
In this work, we study the existence of gradient (proper) CKVs in locally rotationally symmetric spacetimes (LRS), those CKVs in the space spanned by the tangent to observers' congruence and the preferred spatial direction, allowing us to provide a (
Externí odkaz:
http://arxiv.org/abs/2305.05148
Autor:
Sherif, Abbas M., Dunsby, Peter K. S.
In this paper, we study the stability of marginally outer trapped surfaces (MOTS), foliating horizons of the form $r=X(\tau)$, embedded in locally rotationally symmetric class II perfect fluid spacetimes. An upper bound on the area of stable MOTS is
Externí odkaz:
http://arxiv.org/abs/2209.11358
Autor:
Sherif, Abbas M., Dunsby, Peter K. S.
Publikováno v:
Class. Quantum Grav. Vol. 39, 045004, 2022
In this work, we study various properties of embedded hypersurfaces in $1+1+2$ decomposed spacetimes with a preferred spatial direction, denoted $e^{\mu}$, which are orthogonal to the fluid flow velocity of the spacetime and admit a proper conformal
Externí odkaz:
http://arxiv.org/abs/2112.08753
In this work we perform a general study of properties of a class of locally symmetric embedded hypersurfaces in spacetimes admitting a $1+1+2$ spacetime decomposition. The hypersurfaces are given by specifying the form of the Ricci tensor with respec
Externí odkaz:
http://arxiv.org/abs/2112.03219
Autor:
Sherif, Abbas
Publikováno v:
European Physical Journal C, 2021
Let $M$ be a locally rotationally symmetric spacetime with at least one of the rotation or spatial twist being non-zero. It is proved that $M$ cannot admit a non-minimal marginally trapped tube of the form $\chi=X(t)$.
Comment: 6 pages, no figur
Comment: 6 pages, no figur
Externí odkaz:
http://arxiv.org/abs/2105.02913
In this paper we consider homothetic Killing vectors in the class of stationary axisymmetric vacuum (SAV) spacetimes, where the components of the vectors are functions of the time and radial coordinates. In this case the component of any homothetic K
Externí odkaz:
http://arxiv.org/abs/2103.15549