Cosmological dynamics of D-BIonic and DBI scalar field and coincidence problem of dark energy

Sirachak Panpanich, Kei Ichi Maeda, Shuntaro Mizuno

Research output: Contribution to journalArticlepeer-review

6 Citations (Scopus)


We study the cosmological dynamics of a D-BIonic and Dirac-Born-Infeld scalar field, which is coupled to matter fluid. For the exponential potential and the exponential couplings, we find a new analytic scaling solution yielding the accelerated expansion of the Universe. Since it is shown to be an attractor for some range of the coupling parameters, the density parameter of matter fluid can be the observed value, as in the coupled quintessence with a canonical scalar field. Contrary to the usual coupled quintessence, where the value of the matter coupling giving the observed density parameter is too large to satisfy the observational constraint from the cosmic microwave background, we show that the D-BIonic theory can give a similar solution with a much smaller value of matter coupling. As a result, together with the fact that the D-BIonic theory has a screening mechanism, the D-BIonic theory can solve the so-called coincidence problem as well as the dark energy problem.

Original languageEnglish
Article number103520
JournalPhysical Review D
Issue number10
Publication statusPublished - 2017
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy (miscellaneous)


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