Perturbations for Slotheon Field Dark Energy and its Evolution

Abstract

We consider in this work a Slotheon scalar field for Dark Energy. A Slotheon field is inspired by extra dimensional models of Dvali, Gabadadze and Porrati (DGP) related to brane world. In the decoupling limit of this model, the DGP theory in Minkowski space-time is described by a scalar field that obeys a shift symmetry. When extended to curved space time this scalar field is termed as Slotheon field. In this work we calculate general relativistic perturbations by deriving the Dark Energy and matter perturbation equations and solve them numerically. The results are then compared with similar quantities derived from ΛCDM model. It appears that the Slotheon field model for Dark Energy is more akin to Dark energy in ΛCDM model than that in standard Quintessence model. A comparison has also been made between the matter power spectra obtained from Slotheon model and ΛCDM model.