Phantom Energy with Variable G and Lambda
| dc.creator | Arbab, Arbab I. | |
| dc.date | 2007-11-09 | |
| dc.date.accessioned | 2026-07-07T12:21:42Z | |
| dc.date.available | 2026-07-07T12:21:42Z | |
| dc.description | We have investigated a cosmological model of a phantom energy with a variable cosmological constant ($Λ$) depending on the energy density ($ρ$) as $Λ\propto ρ^{-α}$, $α=\rm const.$ and a variable gravitational constant ($G$). The model requires $α<0$ and a negative gravitational constant. A negative gravitational constant may forbid \emph{black holes} to form a particle horizon in a background of phantom energy. This implies that black holes are naked, and consequently the \emph{Cosmic Censorship} theorem is violated. The cosmological constant evolves with time as, $Λ\propto t^{-2}$. For $ω>-1$ and $α<-1$ the cosmological constant, $Λ<0$, $G>0$ and $ρ$ decrease with cosmic expansion. For ordinary matter (or dark matter), i.e., $ω>-1$ we have $-1<α<0$ and $β>0$ so that $G>0$ increases with time and $ρ$ decreases with time. Cosmic acceleration with dust particles is granted provided $-{2/3}<α<0$ and $Λ>0$. | |
| dc.description | 7 pages, revtex4 | |
| dc.identifier | https://arxiv.org/abs/0711.1465 | |
| dc.identifier | http://arxiv.org/abs/0711.1465 | |
| dc.identifier | Chin.Phys.Lett.25:4497-4500,2008 | |
| dc.identifier | doi:10.1088/0256-307X/25/12/088 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/213422 | |
| dc.subject | High Energy Physics - Theory | |
| dc.title | Phantom Energy with Variable G and Lambda | |
| dc.type | text |