Regular Article - Theoretical Physics
A new extended quintessence
Center of Nonlinear Science and Department of Physics, Ningbo University, Ningbo, Zhejiang, 315211, China
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Revised: 14 November 2012
Published online: 27 November 2012
Extended quintessence is obtained by coupling a normal scalar field to the Ricci scalar defined in the metric formalism. In this paper, we propose a new extended quintessence dark energy by introducing a non-minimal coupling between the quintessence and gravity, but with the Ricci scalar given from the Palatini formalism rather than the metric one. We find that the equation of state of the new extended quintessence can cross the phantom divide line, and moreover, it oscillates around the −1 line. We also show that the universe driven by the new extended quintessence will enter a dark energy dominated de Sitter phase in the future.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2012