Explosive phenomena in modified gravity

Abstract

Observational manifestations of some models of modified gravity, which have been suggested to explain the accelerated cosmological expansion, are analyzed for gravitating systems with time dependent mass density. It is shown that if the mass density rises with time, the system evolves to the singular state with infinite curvature scalar. The corresponding characteristic time is typically much shorter than the cosmological time.

10 pages, 3 figures, version published in PLB, a few references are added and the expression for the frequency of oscillations is corrected

References in corpus (9)

• Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
• Disappearing cosmological constant in f(R) gravity
• Tests of the Gravitational Inverse-Square Law below the Dark-Energy Length Scale
• Class of viable modified $f(R)$ gravities describing inflation and the onset of accelerated expansion
• Modified f(R) gravity unifying R^m inflation with \LambdaCDM epoch
• A Singularity Problem with f(R) Dark Energy
• Aspects of cosmological expansion in F(R) gravity models
• Initial and final de Sitter universes from modified $f(R)$ gravity
• Delicate f(R) gravity models with disappearing cosmological constant and observational constraints on the model parameters

Cited by in corpus (38)

• Modified Gravity and Cosmology
• Modified Gravity Theories on a Nutshell: Inflation, Bounce and Late-time Evolution
• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• Reconstruction of $f(T)$ gravity: Rip cosmology, finite-time future singularities and thermodynamics
• Maximal neutron star mass and the resolution of hyperon puzzle in modified gravity
• Causes of Irregular Energy Density in $f(R,T)$ Gravity
• Gravitational collapse in f(R) theories
• The Influence of Modification of Gravity on the Dynamics of Radiating Spherical Fluids
• Cosmological evolution in R^2 gravity
• Some aspects of generalized modified gravity models
• Cosmology Based on f(R) Gravity Admits 1 eV Sterile Neutrinos
• Cavity Evolution and Instability Constraints of Relativistic Interiors
• Large Scale Structure Constraints for a Class of f(R) Theories of Gravity
• Screening of cosmological constant for De Sitter Universe in non-local gravity, phantom-divide crossing and finite-time future singularities
• $\Lambda$CDM Bounce Cosmology without $\Lambda$CDM: the case of modified gravity
• Stability of Anisotropic Stellar Filaments
• An Exponential F(R) Dark Energy Model
• Gravitational Collapse in General Relativity and in $R^2$-gravity: A Comparative Study
• Curvature Singularities from Gravitational Contraction in f(R) Gravity
• Conformally Flat Collapsing Stars in f (R) gravity
• Curvature Oscillations in Modified Gravity and High Energy Cosmic Rays
• Cosmological acceleration
• Gravitationally collapsing stars in $f(R)$ gravity
• Spherically Symmetric Solutions in F(R) Gravity and Gravitational Repulsion
• Intrinsic problems of gravitational baryogenesis
• Particle Production in f(R) Gravity during Structure Formation
• A new approach to cosmological perturbations in f(R) models
• Instability of gravitational baryogenesis with fermions
• Gravitational instability in oscillating background
• Singularity problem in f(R) model with non-minimal coupling
• Curvature Singularity in f(R) Theories of Gravity
• Viability of Arctan Model of f(R) Gravity for Late-time Cosmology
• Cosmological Issues in $F(T)$ Gravity Theory
• Gravitational Collapse of Anisotropic Compact Stars in Modified $f(R)$ Gravity
• No Cosmic Rays from Curvature Oscillations during Structure Formation with $F(R)$-gravity
• Cosmic ray production in modified gravity
• A New f(R) Model in the Light of Local Gravity Test and Late-time Cosmology
• A Note on Gravitational Memory in F(R)-theories and their Equivalent Scalar-Tensor Theories