Gravitational Origin of Phantom Dark Energy and Late Cosmic Acceleration

Abstract

In this letter, dark energy is obtained using dual roles of the Ricci scalar (as a physical field as well as geometry). Dark energy density, obtained here, mimics phantom and the derived Friedmann equation contains a term ${\rho }_{\mathrm{de}}^2/2\lambda$ with ${\rho }_{\mathrm{de}}$ being the dark energy density and $\lambda$ being the cosmic tension. It is like brane-gravity inspired Friedmann equation, which arises without using the brane-gravity theory. It is found that acceleration is transient for $\lambda <0$, but for $\lambda >0$, expansion is found to encounter big-rip problem. It is shown that this problem can be avoided if dark energy behaves as barotropic fluid and generalized Chaplygin gas simultaneously. Moreover, time for transition (from deceleration to acceleration of the universe) is derived as a function of equation of state parameter ${\rm w}_{\rm de} = p_[rm de}/ρ_{\rm de}$ with $p_{\mathrm{de}}$ being the pressure for dark energy fluid..

16 pages

References in corpus (3)

• Cosmology and the Fate of Dilatation Symmetry
• Avoidance of Big Rip In Phantom Cosmology by Gravitational Back Reaction
• Future Universe With w < -1 Without Big Smash

Cited by in corpus (6)

• Quantum Stability of a w < - 1 Phase of Cosmic Acceleration
• Black-Bounce in $f(T)$ Gravity
• Curvature Inspired Cosmological Scenario
• Reconstructing the properties of dark energy from recent observations
• Acceleration and Deceleration in Curvature Induced Phantom Model of the Late and Future Universe, Cosmic Collapse as Well as its Quantum Escape
• A Note on Gravitational Memory in F(R)-theories and their Equivalent Scalar-Tensor Theories