Null Energy Condition and Dark Energy Models
| dc.creator | Qiu, Taotao | |
| dc.creator | Cai, Yi-Fu | |
| dc.creator | Zhang, Xin-Min | |
| dc.date | 2007-09-30 | |
| dc.date.accessioned | 2026-07-07T10:13:08Z | |
| dc.date.available | 2026-07-07T10:13:08Z | |
| dc.description | Null Energy Condition (NEC) requires the equation of state (EoS) of the universe $w_u$ satisfy $w_u\geq-1$, which implies, for instance in a universe with matter and dark energy dominating $w_u=w_mΩ_m+w_{de}Ω_{de}=w_{de}Ω_{de}\geq-1$. In this paper we study constraints on the dark energy models from the requirement of the NEC. We will show that with $Ω_{de}\sim0.7$, $w_{de}<-1$ at present epoch is possible. However, NEC excludes the possibility of $w_{de}<-1$ forever as happened in the Phantom model, but if $w_{de}<-1$ stays for a short period of time as predicted in the Quintom theory NEC can be satisfied. We take three examples of Quintom models of dark energy, namely the phenomenological EoS, the two-scalar-field model and the single scalar model with a modified Dirac-Born-Infeld (DBI) lagrangian to show how this happens. | |
| dc.description | 9 pages, 6 figures | |
| dc.identifier | https://arxiv.org/abs/0710.0115 | |
| dc.identifier | http://arxiv.org/abs/0710.0115 | |
| dc.identifier | Mod.Phys.Lett.A23:2787-2798,2008 | |
| dc.identifier | doi:10.1142/S0217732308026194 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/172421 | |
| dc.subject | General Relativity and Quantum Cosmology | |
| dc.subject | Astrophysics | |
| dc.subject | High Energy Physics - Phenomenology | |
| dc.subject | High Energy Physics - Theory | |
| dc.title | Null Energy Condition and Dark Energy Models | |
| dc.type | text |