FRW-Type Universe With Vacuum Energy Density
| dc.creator | Arbab, Arbab I. | |
| dc.date | 1999-06-14 | |
| dc.date | 2001-05-24 | |
| dc.date.accessioned | 2026-07-07T03:33:15Z | |
| dc.date.available | 2026-07-07T03:33:15Z | |
| dc.description | We have considered a cosmological model with a cosmological constant of the form $Λ=3α\frac{\dot R^2}{R^2}+\bt\frac{\ddot R}{R} α, \bt=\rm const.$ The cosmological constant is found to decrease as $t^{-2}$ and the rate of particle creation is smaller than the Steady State value. We have found that this behavior gives $\frac{Λ_{Pl}}{Λ_p}=10^{120}$ where $Λ_{Pl}$ is the value of $Λ$ at Planck time. Solutions with $\bt=3α$ in the radiation dominated era and $\bt=6α$ in the matter dominated era are equivalent to the FRW results. We have found an inflationary solution of the de-Sitter type with $\bt=3-3α$. Some problems of the Standard Model may be resolved with the presence of the above cosmological constant in the Einstein's equation. Since observations suggest a contribution of the vacuum energy density in the range $0.40<Ω^Λ<0.76$, one gets $4<β<12$. If $α=0$ the minimum age of the universe is found to be $H_p^{-1}$ ($H_p$ is the present Hubble constant) with $β=\infty$. | |
| dc.description | A revised version, 8 pages Latex, submitted to Gravitation and Cosmology | |
| dc.identifier | https://arxiv.org/abs/gr-qc/9906045 | |
| dc.identifier | http://arxiv.org/abs/gr-qc/9906045 | |
| dc.identifier | Grav.Cosmol. 8 (2002) 227-231 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/36549 | |
| dc.subject | General Relativity and Quantum Cosmology | |
| dc.title | FRW-Type Universe With Vacuum Energy Density | |
| dc.type | text |