Why the cosmological constant is small and positive

Paul J. Stainhardt, Neil Turok

Research output: Contribution to journalArticle

86 Scopus citations

Abstract

Within conventional big bang cosmology, it has proven to be very difficult to understand why today's cosmological constant is so small. In this paper, we show that a cyclic model of the universe can naturally incorporate a dynamical mechanism that automatically relaxes the value of the cosmological constant, including contributions to the vacuum density at all energy scales. Because the relaxation time grows exponentially as the vacuum density decreases, nearly every volume of space spends an overwhelming majority of the time at the stage when the cosmological constant is small and positive, as observed today.

Original languageEnglish (US)
Pages (from-to)1180-1183
Number of pages4
JournalScience
Volume312
Issue number5777
DOIs
StatePublished - May 26 2006

All Science Journal Classification (ASJC) codes

  • General

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