Non-flat universe and interacting dark energy model
  For non-flat universe of $k\not=0$, we investigate a model of the interacting holographic dark energy with cold dark matter (CDM). There exists a mixture of two components arisen from decaying of the holographic dark energy into CDM. In this case we use the effective equations of state ($\omega^{\rm eff}_{\rm \Lambda}, \omega^{\rm eff}_{\rm m}$) instead of the native equations of state ($\omega_{\rm \Lambda},\omega_{\rm m})$.   Consequently, we show that interacting holographic energy models in non-flat universe cannot accommodate a transition from the dark energy to the phantom regime. 
Kyong Hee Kim, Hyung Won Lee, Yun Soo Myung