Cosmic Evolution in a Cyclic Universe

By Paul J. Steinhardt, N. Turok. 2001

671 citations recorded by the source corpus.

Based on concepts drawn from the ekpyrotic scenario and M theory, we elaborate our recent proposal of a cyclic model of the universe. In this model, the universe undergoes an endless sequence of cosmic epochs which begin with the universe expanding from a ``big bang'' and end with the universe contracting to a ``big crunch.'' Matching from ``big crunch'' to ``big bang'' is performed according to the prescription recently proposed with Khoury, Ovrut and Seiberg. The expansion part of the cycle includes a period of radiation and matter domination followed by an extended period of cosmic acceleration at low energies. The cosmic acceleration is crucial in establishing the flat and vacuous initial conditions required for ekpyrosis and for removing the entropy, black holes, and other debris produced in the preceding cycle. By restoring the universe to the same vacuum state before each big crunch, the acceleration ensures that the cycle can repeat and that the cyclic solution is an attractor.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/831c394a7a8a37e288f036b02e7b127c30ab7e8e

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Citations in the corpus

Non-singular cosmology in a model of non-relativistic gravity (2009, background): “Recently, the scenario of oscillating universe (originally proposed by [63] and awaked later as ekpyrotic/cyclic by [64–66]), in which the universe experiences a sequence of contractions and expansions, has been widely studied in the literature, for instance in the context of loop quantum gravity [4”
The Matter Bounce Alternative to Inflationary Cosmology (2012, background): “[82] Note that the cyclic version of the Ekpyotic scenario [79] does not face this problem since the evolution of the scale factor of our universe is not cyclic in the model, only the separation between the branes in the higher-dimensional framework of the model.”
Ekpyrotic and cyclic cosmology (2008, background): “Furthermore, in the ekpyrotic or cyclic models, the potential is expected to turn up towards zero at large negative φ (because this corresponds to the limit in heterotic M-theory in which the string coupling approaches zero and the potential disappears [93]), but this detail is irrelevant to the gen”
Cosmology with negative potentials (2002, background): “The cyclic scenario [9] is a modified version of the ekpyrotic scenario [10].”
The black hole final state (2003, background): “Some recent proposals for dealing with the big bang singularity, such as the Ekpyrotic or cyclic models [24, 25] involve singularities which are similar to black hole singularities.”
Time‐dependent orbifolds and string cosmology (2003, positive): “This problem of initial conditions can be solved, within the ekpyrotic setup, with the cyclic model [8], where the observed homogeneity, flatness and density perturbations are dynamically generated by periods of dark energy domination before the bangs.”
A smooth bouncing cosmology with scale invariant spectrum (2007, background): “The pre Big-Bang scenario [1] and the ekpyrotic/cyclic models are different incarnations of these ideas [2, 3].”
Towards inflation in string theory (2003, background): “A more recent version of this scenario, the cyclic scenario [37], uses an infinite number of periods of “superluminal expansion”, i.”
Eternal inflation and its implications (2007, methodology): “One particular application of the theory is the cyclic ekpyrotic model of Steinhardt and Turok [48].”