World Library  
Flag as Inappropriate
Email this Article


Article Id: WHEBN0024864935
Reproduction Date:

Title: Ekpyrotic  
Author: World Heritage Encyclopedia
Language: English
Subject: Shape of the universe, Fine-tuned Universe
Publisher: World Heritage Encyclopedia


The ekpyrotic universe, or ekpyrotic scenario, is a cosmological model of the origin and shape of the universe. The name comes from a Stoic term ekpyrosis (Ancient Greek ἐκπύρωσις ekpurōsis) meaning conflagration or in Stoic usage "conversion into fire".[1] The ekpyrotic model of the universe is an alternative to the standard cosmic inflation model for the very early universe; both models accommodate the standard Big Bang Lambda-CDM model of our universe.[2][3] The ekpyrotic model is a precursor to, and part of, some cyclic models.

The ekpyrotic model came out of work by Neil Turok and Paul Steinhardt and maintains that the universe did not start in a singularity, but came about from the collision of two branes. This collision avoids the primordial singularity and superluminal expansion of spacetime while preserving nearly scale-free density fluctuations and other features of the observed universe. The ekpyrotic model is cyclic, though collisions between branes are rare on the time scale of the expansion of the universe to a nearly featureless flat expanse. Observations that may distinguish between the ekpyrotic and inflationary models include polarization of the cosmic microwave background radiation and frequency distribution of the gravitational wave spectrum.[4][5]

Notes and references

See also

Further reading

  • P. J. Steinhardt and N. Turok, Endless Universe: Beyond the Big Bang, (Doubleday, 2007)
  • A Brief Introduction to the Ekpyrotic Universe Steinhardt, Paul J., Department of Physics, Princeton University
  • Greene, Brian, The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest for the Ultimate Theory, Vintage (2000).
  • Kallosh, Renata, Kofman, Lev and Linde, Andrei, Pyrotechnic Universe (the first paper to point out problems with the theory)
  • Whitehouse, David, "BBC News. April 10, 2001.
  • Discover Magazine, Before the Big Bang February 2004 issue.
  • Parallel Universes, (BBC Two 9.00pm Thursday February 14, 2002)
  • 'Brane-Storm' Challenges Part of Big Bang Theory
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.