Entropy of Contracting Universe in Cyclic Cosmology
| dc.creator | Baum, Lauris | |
| dc.creator | Frampton, Paul H. | |
| dc.date | 2007-03-18 | |
| dc.date.accessioned | 2026-07-07T11:23:44Z | |
| dc.date.available | 2026-07-07T11:23:44Z | |
| dc.description | Following up a recent proposal \cite{BF} for a cyclic model based on phantom dark energy, we examine the content of the contracting universe (cu) and its entropy $S_{cu}$. We find that beyond dark energy the universe contains on average zero or at most a single photon which if present immediately after turnaround has infinitesimally energy which subsequently blue shifts to produce $e^+e^-$ pairs. These statements are independent of the equation of state $ω= p/ρ$ of dark energy provided $ω< -1$. Thus $S_{cu} = 0$ and if observations confirm $ω< -1$ the entropy problem is solved. We discuss the absence of a theoretical lower bound on $ϕ= |ω+ 1|$, then describe an anthropic fine tuning argument that renders unlikely extremely small $ϕ$. The present bound $ϕ\lesssim 0.1$ already implies a time until turnaround of $(t_T - t_0) \gtrsim 100$ Gy. | |
| dc.description | 5 pages latex | |
| dc.identifier | https://arxiv.org/abs/hep-th/0703162 | |
| dc.identifier | http://arxiv.org/abs/hep-th/0703162 | |
| dc.identifier | Mod.Phys.Lett.A23:33-36,2008 | |
| dc.identifier | doi:10.1142/S0217732308026170 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/194990 | |
| dc.subject | High Energy Physics - Theory | |
| dc.title | Entropy of Contracting Universe in Cyclic Cosmology | |
| dc.type | text |