The effect of de Sitter like background on increasing the zero point   budget of dark energy
  During this work, using subtraction renormalization mechanism, zero point quantum fluctuations for bosonic scalar fields in a de-Sitter like background are investigated. By virtue of the observed value for spectral index, $n_s(k)$, for massive scalar field the best value for the first slow roll parameter, $\epsilon$, is achieved. In addition the energy density of vacuum quantum fluctuations for massless scalar field is obtained. The effects of these fluctuations on other components of the Universe are studied. By solving the conservation equation, for some different examples, the energy density for different components of the Universe are obtained. In the case which, all components of the Universe are in an interaction, the different dissipation functions, $\tilde{Q}_{i}$, are considered. The time evolution of ${\rho_{DE}(z)}/{\rho_{cri}(z)}$ shows that $\tilde{Q}=3 \gamma H(t) \rho_{m}$ has best agreement in comparison to observational data including CMB, BAO and SNeIa data set. 
Haidar Sheikhahmadi, Ali Aghamohammadi and Khaled Saaidi
gr-qc