Controlling Chaos through Compactification in Cosmological Models with a Collapsing Phase
| Autor: | Neil Turok, Daniel H. Wesley, Paul J. Steinhardt |
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| Rok vydání: | 2005 |
| Předmět: |
High Energy Physics - Theory
Physics Nuclear and High Energy Physics Compactification (physics) Big Crunch media_common.quotation_subject Kaluza–Klein theory Astrophysics (astro-ph) FOS: Physical sciences General Relativity and Quantum Cosmology (gr-qc) Astrophysics General Relativity and Quantum Cosmology Universe Ekpyrotic universe Gravitation Theoretical physics Classical mechanics High Energy Physics - Theory (hep-th) Quantum cosmology Quantum gravity media_common |
| DOI: | 10.48550/arxiv.hep-th/0502108 |
| Popis: | We consider the effect of compactification of extra dimensions on the onset of classical chaotic "Mixmaster" behavior during cosmic contraction. Assuming a universe that is well-approximated as a four-dimensional Friedmann-Robertson--Walker model (with negligible Kaluza-Klein excitations) when the contraction phase begins, we identify compactifications that allow a smooth contraction and delay the onset of chaos until arbitrarily close the big crunch. These compactifications are defined by the de Rham cohomology (Betti numbers) and Killing vectors of the compactification manifold. We find compactifications that control chaos in vacuum Einstein gravity, as well as in string theories with N = 1 supersymmetry and M-theory. In models where chaos is controlled in this way, the universe can remain homogeneous and flat until it enters the quantum gravity regime. At this point, the classical equations leading to chaotic behavior can no longer be trusted, and quantum effects may allow a smooth approach to the big crunch and transition into a subsequent expanding phase. Our results may be useful for constructing cosmological models with contracting phases, such as the ekpyrotic/cyclic and pre-big bang models. Comment: 1 figure. v2/v3: minor typos corrected |
| Databáze: | OpenAIRE |
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