Evolution of spherical overdensities in new agegraphic dark energy model
  We study the structure formation by investigating the spherical collapse model in the context of new agegraphic dark energy model in flat FRW cosmology. We compute the perturbational quantities $g(a)$, $\delta_{c}(z_{c})$, $\lambda(z_{c})$, $\xi(z_{c})$, $\Delta_{vir}(z_{c})$, $\log[\nu f(\nu)]$ and $\log[n(k)]$ for the new agegraphic dark energy model and compare the results with those of EdS and $\Lambda CDM$ models. We find that there is a dark energy dominated universe at low redshifts and a matter dominated universe at high redshifts in agreement with observations. Also, the size of structures, the overdense spherical region, and the halo size in the new agegraphic dark energy model are found smaller, denser, and larger than those of EdS and $\Lambda CDM$ models. We compare our results with the results of tachyon scalar field and holographic dark energy models. 
M. R. Setare, F. Felegary, F. Darabi
gr-qc