scholarly journals A Cyclic Model of the Universe

Science ◽  
2002 ◽  
Vol 296 (5572) ◽  
pp. 1436-1439 ◽  
Author(s):  
P. J. Steinhardt
Keyword(s):  
Cyclic Model ◽  
The Universe

scholarly journals ENTROPY OF CONTRACTING UNIVERSE IN CYCLIC COSMOLOGY

2008 ◽  
Vol 23 (01) ◽  
pp. 33-36 ◽  
Author(s):  
LAURIS BAUM ◽  
PAUL H. FRAMPTON
Keyword(s):  
Dark Energy ◽  
Equation Of State ◽  
Lower Bound ◽  
Single Photon ◽  
Fine Tuning ◽  
Recent Proposal ◽  
Model Based ◽  
Cyclic Model ◽  
Phantom Dark Energy ◽  
The Universe

Following up a recent proposal1 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 an unlikely single photon which if present immediately after turnaround would have infinitesimal energy that blue shifts eventually 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 ≲ 0.1 already implies a time until turnaround of (tT - t0) ≳ 100 Gy.

Structures in the Universe by Exact Methods

2009 ◽  
Author(s):  
Krzysztof Bolejko ◽  
Andrzej Krasinski ◽  
Charles Hellaby ◽  
Marie-Noelle Celerier
Keyword(s):  
Exact Methods ◽  
The Universe

The Riddle of the Universe at the Close of the Nineteenth Century

2009 ◽  
Author(s):  
Ernst Heinrich Philipp August Haeckel ◽  
Joseph McCabe
Keyword(s):  
Nineteenth Century ◽  
The Universe
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