Structure formation and CMBR anisotropy spectrum in the inflessence model

The inflessence model has recently been proposed in an attempt to explain both early inflation and present day accelerated expansion within a single mechanism. The model has been successfully tested against the Hubble diagram of Type Ia Supernovae, the shift parameter, and the acoustic peak parameter. As a further mandatory test, we investigate here structure formation in the inflessence model determining the evolution of matter density contrast d equivalent to dln delta/dlna in the linear regime. We compare the growth factor D(a) equivalent to delta/a and the growth index f(z) equivalent to dln delta/dlna to these same quantities for the successful concordance boolean AND CDM model with a particular emphasis on the role of the inflessence parameters (gamma, z(Q)). We also evaluate the anisotropy spectrum of the cosmic microwave background radiation (CMBR) to check whether the inflessence model may be in agreement with the observations. We find that, for large values of (gamma, z(Q)), structure formation proceeds in a similar way to that in the boolean AND CDM scenario, and it is also possible to nicely fit the CMBR spectrum.