Horizon Entropy in Modified Gravity

Abstract

We present an observation about the proposal that four-dimensional modification of general relativity may explain the observed cosmic acceleration today. Assuming that the thermodynamical nature of gravity theory continues to hold in modified gravity theories, we derive the modified horizon entropy formula from the modified Friedmann equation. We argue that our results imply that there are conceptual problems in some models of four-dimensional modification of general relativity.

8 pages. v2: references added

References in corpus (5)

• The Cosmology of Generalized Modified Gravity Models
• One-loop f(R) gravity in de Sitter universe
• Consistent modified gravity: dark energy, acceleration and the absence of cosmic doomsday
• Ghost Constraints on Modified Gravity
• Palatini formulation of the $R^{-1}$modified gravity with an additionally squared scalar curvature term

Cited by in corpus (35)

• f(R) Theories Of Gravity
• Friedmann Equations of FRW Universe in Scalar-tensor Gravity, f(R) Gravity and First Law of Thermodynamics
• Generalized Uncertainty Principle: Approaches and Applications
• Matter instability in modified gravity
• The (pseudo)issue of the conformal frame revisited
• The stability of modified gravity models
• de Sitter space and the equivalence between f(R) and scalar-tensor gravity
• Solar System experiments do not yet veto modified gravity models
• Thermodynamics of cosmological horizons in $f(T)$ gravity
• A viability criterion for modified gravity with an extra force
• Accelerated cosmos in a non-extensive setup
• Thermodynamics in $F(R)$ gravity with phantom crossing
• The phase space view of f(R) gravity
• Modified gravity and the stability of de Sitter space
• Thermodynamics in $f(R)$ gravity in the Palatini formalism
• The Cauchy problem of f(R) gravity
• Black hole entropy in scalar-tensor and f(R) gravity: an overview
• Generalized second law in modified theory of gravity
• Making sense of the bizarre behaviour of horizons in the McVittie spacetime
• Noether Charge and Black Hole Entropy in Modified Theories of Gravity
• Thermodynamic properties of modified gravity theories
• Are quantization rules for horizon areas universal?
• Testing the DGP model with gravitational lensing statistics
• An analysis of the Sultana-Dyer cosmological black hole solution of the Einstein equations
• Thermodynamics of a Schwarzschild Black Hole in Phantom Cosmology with Entropy Corrections
• Modified gravity emerging from thermodynamics and holographic principle
• Generalized Second Law of Thermodynamics in Extended Theories of Gravity
• On thermodynamics second law in the modified Gauss Bonnet gravity
• The generalized second law in chameleon cosmology
• Thermodynamics of Anomaly-Driven Cosmology
• Dynamical apparent horizons in inhomogeneous Brans-Dicke universes
• Modified Newton's Law of Gravitation Due to Minimal Length in Quantum Gravity
• Improved method for the experimental determination of in-medium effects from heavy-ion collisions
• The Unified First law in "Cosmic Triad" Vector Field Scenario
• D-bound and Bekenstein bound for McVittie solution surrounded by dark energy cosmological fields