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New Perspective on Cosmic Coincidence Problems

Nima Arkani-Hamed, Lawrence J. Hall, Christopher Kolda, and Hitoshi Murayama
Phys. Rev. Lett. 85, 4434 – Published 20 November 2000
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Abstract

Cosmological data suggest that we live in an interesting period in the history of the universe when ρΛρMρR. The occurrence of any epoch with such a “triple coincidence” is puzzling, while the question of why we happen to live during this special epoch is the “Why now?” problem. We introduce a framework which makes the triple coincidence inevitable; furthermore, the “Why now?” problem is transformed and greatly ameliorated. The framework assumes that the only relevant mass scales are the electroweak scale MEW, and the Planck scale MPl and requires ρΛ1/4MEW2/MPl parametrically. Assuming that the true vacuum energy vanishes, we present a simple model, where a false vacuum energy yields a cosmological constant of this form.

  • Received 5 June 2000

DOI:https://doi.org/10.1103/PhysRevLett.85.4434

©2000 American Physical Society

Authors & Affiliations

Nima Arkani-Hamed, Lawrence J. Hall, Christopher Kolda, and Hitoshi Murayama

  • Department of Physics, University of California, Berkeley, California 94720 Theoretical Physics Group, Lawrence Berkeley National Laboratory, Berkeley, California 94720

See Also

Why Now?

Robert Matthews
Phys. Rev. Focus 6, 22 (2000)

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Issue

Vol. 85, Iss. 21 — 20 November 2000

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