%0 Generic %1 baum2007entropy %A Baum, Lauris %A Frampton, Paul H. %D 2007 %K contracting cosmology cyclic entropy universe %R 10.1142/S0217732308026170 %T Entropy of Contracting Universe in Cyclic Cosmology %U http://arxiv.org/abs/hep-th/0703162 %X Following up a recent proposal 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 $= p/\rho$ of dark energy provided $< -1$. Thus $S_cu = 0$ and if observations confirm $< -1$ the entropy problem is solved. We discuss the absence of a theoretical lower bound on $= |+ 1|$, then describe an anthropic fine tuning argument that renders unlikely extremely small $\phi$. The present bound $0.1$ already implies a time until turnaround of $(t_T - t_0) 100$ Gy.

@misc{baum2007entropy, abstract = {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 $\omega = p/\rho$ of dark energy provided $\omega < -1$. Thus $S_{cu} = 0$ and if observations confirm $\omega < -1$ the entropy problem is solved. We discuss the absence of a theoretical lower bound on $\phi = |\omega + 1|$, then describe an anthropic fine tuning argument that renders unlikely extremely small $\phi$. The present bound $\phi \lesssim 0.1$ already implies a time until turnaround of $(t_T - t_0) \gtrsim 100$ Gy.}, added-at = {2013-12-23T11:45:26.000+0100}, author = {Baum, Lauris and Frampton, Paul H.}, biburl = {https://www.bibsonomy.org/bibtex/2049c7c0f23c0aa8b91f7b82a3d85918e/aeu_research}, description = {Entropy of Contracting Universe in Cyclic Cosmology}, doi = {10.1142/S0217732308026170}, interhash = {a838893b521ccb976fd312b46b0a1f42}, intrahash = {049c7c0f23c0aa8b91f7b82a3d85918e}, keywords = {contracting cosmology cyclic entropy universe}, note = {cite arxiv:hep-th/0703162Comment: 5 pages latex}, timestamp = {2013-12-23T11:45:26.000+0100}, title = {Entropy of Contracting Universe in Cyclic Cosmology}, url = {http://arxiv.org/abs/hep-th/0703162}, year = 2007 }