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Gauss-Bonnet dark energy

Shin'ichi Nojiri·Sergei D. Odintsov·Misao Sasaki
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Abstract

We propose the Gauss-Bonnet dark energy model inspired by string/M-theory where standard gravity with scalar contains additional scalar-dependent coupling with Gauss-Bonnet invariant. It is demonstrated that effective phantom (or quintessence) phase of late universe may occur in the presence of such term when the scalar is phantom or for non-zero potential (for canonical scalar). However, with the increase of the curvature the GB term may become dominant so that phantom phase is transient and $w=-1$ barrier may be passed. Hence, the current acceleration of the universe may be caused by mixture of scalar phantom and (or) potential/stringy effects. It is remarkable that scalar-Gauss-Bonnet coupling acts against the Big Rip occurence in phantom cosmology.

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Shin'ichi Nojiri, Sergei D. Odintsov, Misao Sasaki. 2005-05-25. Gauss-Bonnet dark energy. https://doi.org/10.1103/physrevd.71.123509

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