Remarks on Dynamical Dark Energy Measured by the Conformal Age of the Universe
| dc.creator | Neupane, Ishwaree P. | |
| dc.date | 2007-09-20 | |
| dc.date | 2007-12-03 | |
| dc.date.accessioned | 2026-07-07T11:37:20Z | |
| dc.date.available | 2026-07-07T11:37:20Z | |
| dc.description | We elaborate on a model of conformal dark energy (dynamical dark energy measured by the conformal age of the universe) recently proposed in [H. Wei and R.G. Cai, arXiv:0708.0884] where the present-day dark energy density was taken to be $ρ_q \equiv 3 α^2 m_P^2/η^2$, where $η$ is the conformal time and $α$ is a numerical constant. In the absence of an interaction between the ordinary matter and dark energy field $q$, the model may be adjusted to the present values of the dark energy density fraction $Ω\Z{q} \simeq 0.73$ and the equation of state parameter $w\Z{q} < -0.78$, if the numerical constant $α$ takes a reasonably large value, $α\gtrsim 2.6$. However, in the presence of a nontrivial gravitational coupling of $q$-field to matter, say $\widetilde{Q}$, the model may be adjusted to the values $Ω\Z{q}\simeq 0.73$ and $w\Z{q}\simeq -1$, even if $α\sim {\cal O}(1)$, given that the present value of $\widetilde{Q}$ is large. Unlike for the model in [R.G. Cai, arXiv:0707.4049], the bound $Ω\Z{q} <0.1$ during big bang nucleosynthesis (BBN) may be satisfied for almost any value of $α$. Here we discuss some other limitations of this proposal as a viable dark energy model. The model draws some parallels with the holographic dark energy; we also briefly comment on the latter model. | |
| dc.description | 16 pages, 10 figures, a reference added, the version to appear in Phys. Rev. D | |
| dc.identifier | https://arxiv.org/abs/0709.3096 | |
| dc.identifier | http://arxiv.org/abs/0709.3096 | |
| dc.identifier | Phys.Rev.D76:123006,2007 | |
| dc.identifier | doi:10.1103/PhysRevD.76.123006 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/199172 | |
| dc.subject | High Energy Physics - Theory | |
| dc.subject | Astrophysics | |
| dc.subject | General Relativity and Quantum Cosmology | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.title | Remarks on Dynamical Dark Energy Measured by the Conformal Age of the Universe | |
| dc.type | text |