Assisted dark energy

Junko Ohashi; Shinji Tsujikawa

Assisted dark energy

Research output: Contribution to conference › Paper › peer-review

Abstract

We study cosmological dynamics of a multi-field system for a general Lagrangian density having scaling solutions. This allows the possibility that scaling radiation and matter eras are followed by a late-time cosmic acceleration through an assisted inflation mechanism. Using the bound coming from Big-Bang-Nucleosynthesis (BBN) and the condition under which each field cannot drive inflation as a single component of the universe, we find the following features: (i) a transient or eternal cosmic acceleration can be realized after the scaling matter era, (ii) a "thawing" property of assisting scalar fields is crucial to determine the evolution of the field equation of state w_φ, and (iii) the field equation of state today can be consistent with the observational bound w_φin the presence of multiple scalar fields.

Original language	English
Pages	279-282
Number of pages	4
Publication status	Published - 2009
Externally published	Yes
Event	19th Workshop on General Relativity and Gravitation in Japan, JGRG 2009 - Tokyo, Japan Duration: 2009 Nov 30 → 2009 Dec 4

Conference

Conference	19th Workshop on General Relativity and Gravitation in Japan, JGRG 2009
Country/Territory	Japan
City	Tokyo
Period	09/11/30 → 09/12/4

ASJC Scopus subject areas

Atomic and Molecular Physics, and Optics

Cite this

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title = "Assisted dark energy",

abstract = "We study cosmological dynamics of a multi-field system for a general Lagrangian density having scaling solutions. This allows the possibility that scaling radiation and matter eras are followed by a late-time cosmic acceleration through an assisted inflation mechanism. Using the bound coming from Big-Bang-Nucleosynthesis (BBN) and the condition under which each field cannot drive inflation as a single component of the universe, we find the following features: (i) a transient or eternal cosmic acceleration can be realized after the scaling matter era, (ii) a {"}thawing{"} property of assisting scalar fields is crucial to determine the evolution of the field equation of state wφ, and (iii) the field equation of state today can be consistent with the observational bound wφin the presence of multiple scalar fields.",

author = "Junko Ohashi and Shinji Tsujikawa",

year = "2009",

language = "English",

pages = "279--282",

note = "19th Workshop on General Relativity and Gravitation in Japan, JGRG 2009 ; Conference date: 30-11-2009 Through 04-12-2009",

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TY - CONF

T1 - Assisted dark energy

AU - Ohashi, Junko

AU - Tsujikawa, Shinji

PY - 2009

Y1 - 2009

N2 - We study cosmological dynamics of a multi-field system for a general Lagrangian density having scaling solutions. This allows the possibility that scaling radiation and matter eras are followed by a late-time cosmic acceleration through an assisted inflation mechanism. Using the bound coming from Big-Bang-Nucleosynthesis (BBN) and the condition under which each field cannot drive inflation as a single component of the universe, we find the following features: (i) a transient or eternal cosmic acceleration can be realized after the scaling matter era, (ii) a "thawing" property of assisting scalar fields is crucial to determine the evolution of the field equation of state wφ, and (iii) the field equation of state today can be consistent with the observational bound wφin the presence of multiple scalar fields.

AB - We study cosmological dynamics of a multi-field system for a general Lagrangian density having scaling solutions. This allows the possibility that scaling radiation and matter eras are followed by a late-time cosmic acceleration through an assisted inflation mechanism. Using the bound coming from Big-Bang-Nucleosynthesis (BBN) and the condition under which each field cannot drive inflation as a single component of the universe, we find the following features: (i) a transient or eternal cosmic acceleration can be realized after the scaling matter era, (ii) a "thawing" property of assisting scalar fields is crucial to determine the evolution of the field equation of state wφ, and (iii) the field equation of state today can be consistent with the observational bound wφin the presence of multiple scalar fields.

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T2 - 19th Workshop on General Relativity and Gravitation in Japan, JGRG 2009

Y2 - 30 November 2009 through 4 December 2009

ER -

Assisted dark energy

Abstract

Conference

ASJC Scopus subject areas

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