Geometric model of dark energy
| dc.creator | Folomeev, V. | |
| dc.creator | Gurovich, V. | |
| dc.creator | Kleinert, H. | |
| dc.date | 2005-01-12 | |
| dc.date | 2005-02-03 | |
| dc.date.accessioned | 2026-07-07T02:16:42Z | |
| dc.date.available | 2026-07-07T02:16:42Z | |
| dc.description | A cosmological model with a gravitational Lagrangian $L_g(R)\propto R+A R^n$ is set up to account for the presently observed re-acceleration of the universe. The evolution equation for the scale factor $a$ of the universe is analyzed in detail for the two parameters $n=2$ and $n=4/3$, which were preferred by previous studies of the early universe. The initial conditions are specified at a red-shift parameter $z\approx 0$. The fit to the observable data fixes the free parameter $A$. The analysis shows that the model with $n=2$ agrees better with present data. Then, if we set $w(q)=-1$ at $z=0$, corresponding to the deceleration parameter $q\approx -1/2$, we find that at $z\approx 0.5$, $w(q)$ has evolved to $w\approx -0.72$, corresponding to $q\approx 0$. At $z\approx 1$ we find $w\approx 0$ corresponding to $q\approx 1/2$. These results are compared with the flat Friedmann model with cold matter and Lambda-term (LCDM model) for the same initial conditions at $z\approx 0$. The other choice of the model with $n=4/3$ allows for big crunch. However this possibility is eliminated by the fit of $A$ to the present data. | |
| dc.description | 8 pages, 1 figure, added reference, corrected the title of the figure | |
| dc.identifier | https://arxiv.org/abs/astro-ph/0501209 | |
| dc.identifier | http://arxiv.org/abs/astro-ph/0501209 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/8888 | |
| dc.subject | Astrophysics | |
| dc.title | Geometric model of dark energy | |
| dc.type | text |