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Title: Quintessence, Cosmic Coincidence, and the Cosmological Constant

Abstract

Recent observations suggest that a large fraction of the energy density of the Universe has negative pressure. One explanation is vacuum energy density; another is quintessence in the form of a scalar field slowly evolving down a potential. In either case, a key problem is to explain why the energy density nearly coincides with the matter density today. The densities decrease at different rates as the Universe expands, so coincidence today appears to require that their ratio be set to a specific, infinitesimal value in the early Universe. In this paper, we introduce the notion of a {open_quotes}tracker field,{close_quotes} a form of quintessence, and show how it may explain the coincidence, adding new motivation for the quintessence scenario. {copyright} {ital 1999} {ital The American Physical Society}

Authors:
; ;  [1];  [2]
  1. Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)
  2. Department of Physics, Princeton University, Princeton, New Jersey 08540 (United States)
Publication Date:
Research Org.:
Princeton Univ., NJ (United States)
OSTI Identifier:
304264
DOE Contract Number:  
FG02-91ER40671; FG02-95ER40893
Resource Type:
Journal Article
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 82; Journal Issue: 5; Other Information: PBD: Feb 1999
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; COSMOLOGY; NONLUMINOUS MATTER; COSMOLOGICAL CONSTANT; COSMOLOGICAL MODELS

Citation Formats

Zlatev, I., Wang, L., Steinhardt, P.J., and Steinhardt, P.J. Quintessence, Cosmic Coincidence, and the Cosmological Constant. United States: N. p., 1999. Web. doi:10.1103/PhysRevLett.82.896.
Zlatev, I., Wang, L., Steinhardt, P.J., & Steinhardt, P.J. Quintessence, Cosmic Coincidence, and the Cosmological Constant. United States. doi:10.1103/PhysRevLett.82.896.
Zlatev, I., Wang, L., Steinhardt, P.J., and Steinhardt, P.J. Mon . "Quintessence, Cosmic Coincidence, and the Cosmological Constant". United States. doi:10.1103/PhysRevLett.82.896.
@article{osti_304264,
title = {Quintessence, Cosmic Coincidence, and the Cosmological Constant},
author = {Zlatev, I. and Wang, L. and Steinhardt, P.J. and Steinhardt, P.J.},
abstractNote = {Recent observations suggest that a large fraction of the energy density of the Universe has negative pressure. One explanation is vacuum energy density; another is quintessence in the form of a scalar field slowly evolving down a potential. In either case, a key problem is to explain why the energy density nearly coincides with the matter density today. The densities decrease at different rates as the Universe expands, so coincidence today appears to require that their ratio be set to a specific, infinitesimal value in the early Universe. In this paper, we introduce the notion of a {open_quotes}tracker field,{close_quotes} a form of quintessence, and show how it may explain the coincidence, adding new motivation for the quintessence scenario. {copyright} {ital 1999} {ital The American Physical Society}},
doi = {10.1103/PhysRevLett.82.896},
journal = {Physical Review Letters},
number = 5,
volume = 82,
place = {United States},
year = {1999},
month = {2}
}