Turnaround in Cyclic Cosmology
Abstract
It is speculated how dark energy in a brane world can help reconcile an infinitely cyclic cosmology with the second law of thermodynamics. A cyclic model is described, in which dark energy with w<1 equation of state leads to a turnaround at a time, extremely shortly before the wouldbe big rip, at which both volume and entropy of our Universe decrease by a gigantic factor, while very many independent similarly small contracting universes are spawned. The entropy of our model decreases almost to zero at turnaround but increases for the remainder of the cycle by a vanishingly small amount during contraction, empty of matter, then by a large factor during inflationary expansion.
 Publication:

Physical Review Letters
 Pub Date:
 February 2007
 DOI:
 10.1103/PhysRevLett.98.071301
 arXiv:
 arXiv:astroph/0608138
 Bibcode:
 2007PhRvL..98g1301B
 Keywords:

 98.80.Cq;
 11.25.Wx;
 95.36.+x;
 Particletheory and fieldtheory models of the early Universe;
 String and brane phenomenology;
 Dark energy;
 Astrophysics;
 General Relativity and Quantum Cosmology;
 High Energy Physics  Phenomenology;
 High Energy Physics  Theory
 EPrint:
 11 pages latex