Oscillations of the F(R) dark energy in the accelerating universe

Abstract

Oscillations of the $F(R)$ dark energy around the phantom divide line, ${\omega }_{DE}=-1$, both during the matter era and also in the de Sitter epoch are investigated. The analysis during the de Sitter epoch is revisited by expanding the modified equations of motion around the de Sitter solution. Then, during the matter epoch, the time dependence of the dark energy perturbations is discussed by using two different local expansions. For high values of the red shift, the matter epoch is a stable point of the theory, giving the possibility to expand the $F(R)$-functions in terms of the dark energy perturbations. In the late-time matter era, the realistic case is considered where dark energy tends to a constant. The results obtained are confirmed by precise numerical computation on a specific model of exponential gravity. A novel and very detailed discussion is provided on the critical points in the matter era and on the relation of the oscillations with possible singularities.

23 pages, 11 figures, version to appear in EPJC

References in corpus (17)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Extended Theories of Gravity
• Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
• Class of viable modified $f(R)$ gravities describing inflation and the onset of accelerated expansion
• Cosmological viability of f(R)-gravity as an ideal fluid and its compatibility with a matter dominated phase
• Conditions for the cosmological viability of f(R) dark energy models
• Future of the universe in modified gravitational theories: Approaching to the finite-time future singularity
• The future evolution and finite-time singularities in $F(R)$-gravity unifying the inflation and cosmic acceleration
• Dark Energy: the equation of state description versus scalar-tensor or modified gravity
• Matter instability in modified gravity
• Non-singular exponential gravity: a simple theory for early- and late-time accelerated expansion
• Models for Little Rip Dark Energy
• Cosmological evolution in exponential gravity
• On the Stability of a class of Modified Gravitational Models
• Cyclic, ekpyrotic and little rip universe in modified gravity
• Observational Constraints on Exponential Gravity
• Future Oscillations around Phantom Divide in f(R) Gravity

Cited by in corpus (29)

• Modified Gravity Theories on a Nutshell: Inflation, Bounce and Late-time Evolution
• Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A${}^{\ast }$
• Mimetic gravity: a review of recent developments and applications to cosmology and astrophysics
• Revisiting a negative cosmological constant from low-redshift data
• Unification of Constant-roll Inflation and Dark Energy with Logarithmic $R^2$-corrected and Exponential $F(R)$ Gravity
• Cosmic history of viable exponential gravity: Equation of state oscillations and growth index from inflation to dark energy era
• Some aspects of generalized modified gravity models
• Accelerating Cosmology and Phase Structure of F(R) Gravity with Lagrange Multiplier Constraint: Mimetic Approach
• Viable Mimetic Completion of Unified Inflation-Dark Energy Evolution in Modified Gravity
• Spherically symmetric black holes in $f(R)$ gravity: Is geometric scalar hair supported ?
• FRW Cosmology in $f(Q,T)$ Gravity
• A Panorama of Viable $F(R)$ Gravity Dark Energy Models
• An Exponential F(R) Dark Energy Model
• Beyond-one-loop quantum gravity action yielding both inflation and late-time acceleration
• Qualitative analysis of Kantowski-Sachs metric in a generic class of $f(R)$ models
• Dark Energy Oscillations in Mimetic $F(R)$ Gravity
• Cosmological evolution, future singularities, Little Rip and Pseudo-Rip in viable f(R) theories and their scalar-tensor counterpart
• Dark Energy and Equation of State Oscillations with Collisional Matter Fluid in Exponential Modified Gravity
• Late-time cosmological evolution of a general class of f(R, T) gravity with minimal curvature-matter coupling
• Aspects of Late-time Evolution in Mimetic $F(R)$ Gravity
• Solar System tests and chameleon effect in f (R) gravity
• Linear perturbations in viable f(R) theories
• Topological electro-vacuum solutions in extended gravity
• Singularity problem in f(R) model with non-minimal coupling
• A New Exponential Gravity
• Non-linear density-velocity dynamics in $f(R)$ gravity from spherical collapse
• Cosmic acceleration in asymptotically Ricci flat Universe
• A Note on Gravitational Memory in F(R)-theories and their Equivalent Scalar-Tensor Theories
• Non-singular Bouncing Cosmology in $f(R,G,T)$--Quintom model