The evolutionary pictures for phantom field in loop quantum cosmology

摘要

The evolutionary pictures for phantom field in loop quantum cosmology are discussed in this paper. Comparing the dynamical behaviors of the phantom field with one of the canonical scalar fields in loop quantum cosmology scenario, we found that the H - rho phase trajectories are the same, but the phi - (phi) over dot phase-spaces are very different, and the phantom field with considering potentials can drive neither super inflation nor slow-roll inflation in loop quantum cosmology (LQC) scenario. While the universe is filled with multiple dark fluids, to ensure that the condition V <= rho(c) does not violate, the energy density of dark matter rho(DM) and the equation-of-state of phantom field omega(Ph) should satisfy the condition rho(DM)/rho(c) > (-1 - omega(Ph))/(1 - omega(Ph)) at the bounce point. If this constraint condition holds, the universe can enter an inflationary stage, and it is possible to unify the description of phantom field, dark matter and inflation. We introduced a toy model which has the same form of the general Chaplygin gas to unify the dark energy, dark matter and slow-roll inflation, and the slow-roll inflation of the toy model has also been discussed.