Aspects of Late-time Evolution in Mimetic $F(R)$ Gravity

Abstract

We demonstrate how to describe in an unified way early and late-time acceleration in the context of mimetic $F(R)$ gravity. As we show, an exponential $F(R)$ gravity model has appealing features, with regard to unification, and we perform an analysis of the late-time evolution. The resulting picture is interesting since in the mimetic case, certain pathologies of some ordinary $F(R)$ models are remedied in a consistent way, owing to the presence of the mimetic potential and the Lagrange multiplier. We quantify the late-time evolution analysis by studying the scaled dark energy density, the dark energy equation of state and the total effective equation of state, and as we show the late-time evolution is crucially affected by the functional form of the $F(R)$ gravity. It is intriguing that the most appealing case corresponds to the exponential $F(R)$ gravity which unifies late and early-time acceleration. Finally, we study the behavior of the effective gravitational constant and the growth factor, and as we show, significant differences between the mimetic and ordinary $F(R)$ exponential model are spotted in the growth factor.

MPLA accepted

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Cited by in corpus (11)

• Mimetic gravity: a review of recent developments and applications to cosmology and astrophysics
• Ghost-Free $F(R)$ Gravity with Lagrange Multiplier Constraint
• Higher Derivative Mimetic Gravity
• Late time cosmological approach in mimetic $f(R,T)$ gravity
• Event Horizon Telescope observations exclude compact objects in baseline mimetic gravity
• Primordial Cosmology in Mimetic Born-Infeld Gravity
• The key role of Lagrangian multiplier in mimetic gravitational theory in the frame of isotropic compact star
• Consistency between black hole and mimetic gravity -- Case of $(2+1)$-dimensional gravity
• Structure formation in mimetic gravity
• Black holes with Lagrange multiplier and potential in mimetic-like gravitational theory: multi-horizon black holes
• Isotropic stellar model in mimetic theory