Brane tachyon dynamics

Understand

The dynamics of a tachyon attached to a Dvali, Gabadadze and Porrati (DGP) brane is investigated.

• Exponential potential and inverse power law potential are explored, respectively.
• The quasi-attractor behavior, for which the universe will eventually go into a phase similar to the slow-roll inflation, is discovered in both cases of exponential potential and inverse power law potential.
• The equation of state (EOS) of the virtual dark energy for a single scalar can cross the phantom divide in the branch $\theta=-1$ for both potentials, while the EOS of the virtual dark energy for a single scalar can not cross this divide in the branch $\theta=1$.