Zobrazeno 1 - 10
of 227
pro vyhledávání: '"Dunsby, Peter K S"'
Publikováno v:
Phys. Rev. D 110, 043505 (2024)
We perform a detailed dynamical system analysis for the behaviour of a Dirac-Born-Infeld (DBI) field in a spatially closed Friedmann-Lema\^itre-Robertson-Walker (FLRW) cosmology. The DBI field is characterised by a potential and brane tension. We stu
Externí odkaz:
http://arxiv.org/abs/2405.06031
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 present a dynamical system formulation for inhomogeneous LRS-II spacetimes using the covariant 1+1+2 decomposition approach. Our approach describes the LRS-II dynamics from the point of view of a comoving observer. Promoting the covariant radial d
Externí odkaz:
http://arxiv.org/abs/2404.01161
We consider a double polytropic cosmological fluid and demonstrate that, when one constituent resembles a bare cosmological constant while the other emulates a generalized Chaplygin gas, a good description of the Universe's large-scale dynamics is ob
Externí odkaz:
http://arxiv.org/abs/2403.17880
We present a covariant description of non-vacuum static spherically symmetric spacetimes in $f(R)$ gravity applying the (1+1+2) covariant formalism. The propagation equations are then used to derive a covariant and dimensionless form of the Tolman-Op
Externí odkaz:
http://arxiv.org/abs/2403.00070
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
We explore a generalised unified dark energy model that incorporates a non-minimal interaction between a tachyonic fluid and an additional scalar field. Specifically, we require that the second field possesses a vacuum energy, introducing an inelimin
Externí odkaz:
http://arxiv.org/abs/2308.15776
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
A number of dynamical system formulations have been proposed over the last few years to analyse cosmological solutions in $f(R)$ gravity. The aim of this article is to provide a brief introduction to the different approaches, presenting them in chron
Externí odkaz:
http://arxiv.org/abs/2112.13094
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