We consider the future dynamics of a transient phantom dominated phase of the universe in loop quantum cosmology (LQC) and in the Randall-Sundrum braneworld, which both have a nonstandard Friedmann equation. We find that for a certain class of potentials, the Hubble parameter oscillates with simple harmonic motion in the LQC case and therefore avoids any future singularity. For more general potentials we find that damping effects eventually lead to the Hubble parameter becoming constant. On the other hand in the braneworld case we find that although the type I singularity can be avoided, the scale factor still diverges at late times.

• Received 11 June 2007

DOI:https://doi.org/10.1103/PhysRevD.76.063514