Singular Accelerated Evolution in Massive $F(R)$ Bigravity

Abstract

The possibility to have singular accelerated evolution in the context of $F(R)$ bimetric gravity is investigated. Particularly, we study two singular models of cosmological evolution, one of which is a singular modified version of the Starobinsky $R^2$ inflation model. As we demonstrate, for both models in some cases, the slow-roll parameters become singular at the Type IV singularity, a fact that we interpret as a dynamical instability of the theory under study. This dynamically instability may be an indicator of graceful exit from inflation and we thoroughly discuss this scenario and the interpretation of the singular slow-roll parameters. Furthermore, it is demonstrated that for some versions of $F(R)$ bigravity, singular inflation is realized in consistent way so that inflationary indices are compatible with Planck data. Moreover, we study the late-time behavior of the two singular models and we show that the unified description of early and late-time acceleration can be achieved in the context of bimetric $F(R)$ gravity.

References in corpus (23)

• Unified cosmic history in modified gravity: from F(R) theory to Lorentz non-invariant models
• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• Resummation of Massive Gravity
• Beyond the Cosmological Standard Model
• Inflationary cosmology in modified gravity theories
• Bimetric gravity is cosmologically viable
• Worse than a big rip?
• On couplings to matter in massive (bi-)gravity
• Classification of cosmological milestones
• Quantum phantom cosmology
• Avoidance of Big Rip In Phantom Cosmology by Gravitational Back Reaction
• Singular Inflationary Universe from $F(R)$ Gravity
• On the quantum fate of singularities in a dark-energy dominated universe
• On the generalised Chaplygin gas: worse than a big rip or quieter than a sudden singularity?
• Massive gravity from bimetric gravity
• Classical Stability of Sudden and Big Rip Singularities
• Viscous Dark Cosmology with Account of Quantum Effects
• Singular Inflation
• A quantitative analysis of singular inflation with scalar-tensor and modified gravity
• Singular fate of the universe in modified theories of gravity
• Astronomical bounds on future big freeze singularity
• Bounces, turnarounds and singularities in bimetric gravity
• New mechanism to cross the phantom divide

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• Finite-time Cosmological Singularities and the Possible Fate of the Universe
• Correspondence of $F(R)$ Gravity Singularities in Jordan and Einstein Frames
• Unimodular $F(R)$ Gravity
• Propagating speed of primordial gravitational waves and inflation
• Bimetric-Affine Quadratic Gravity
• Bimetric Starobinsky model
• On the Expanding Phase of a Singular Bounce and Intermediate Inflation: The Modified Gravity Description
• GR-GSG Hybrid Gravity