Zobrazeno 1 - 10
of 226
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 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
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