Cosmic Evolution in a Cyclic Universe

Abstract

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 insures that the cycle can repeat and that the cyclic solution is an attractor.

49 pages, 6 figures, minor corrections plus added discussions on geodesic completeness, the role of the scale factor and the bounce

References in corpus (2)

• The Ekpyrotic Universe: Colliding Branes and the Origin of the Hot Big Bang
• From Big Crunch to Big Bang

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• Breaking Free from the Swampland of Impossible Universes through the DESI Portal
• The emergent Big Bang scenario
• The Genesis of the Big-Bang and Inflation
• The Darboux Transformation and Exactly Solvable Cosmological Models
• Theoretical and observational aspects of cosmological inflation
• Conformally coupled inflation
• Primordial Fluctuations in String Cosmology
• Conformal structure of singularities in some varying fundamental constants bimetric cosmologies
• Modelling cosmological singularity with compactified Milne space
• Bounce and stability in the early cosmology with anomaly-induced corrections
• Quantum Entanglement on Cosmological Scale
• Propagation of extended objects across singularity of time dependent orbifold
• The cosmological constant as an eigenvalue of a Sturm-Liouville problem
• Power-law cosmologies in minimal and maximal gauged supergravity
• Uniformity of Cosmic Microwave Background as a Non-Inflationary Geometrical Effect
• Cosmological Asymptotics in Higher-Order Gravity Theories
• A cyclic universe with colour fields
• Cosmological backreaction of heavy string states