Sign Switching Dark Energy from a Running Barrow Entropy

Abstract

Barrow proposed that the area law of the entropy associated with a horizon might receive a "fractal correction" due to quantum gravitational effects -- in place of $S\propto A$, we have instead $S\propto A^{1+\delta /2}$, where $0⩽\delta ⩽1$ measures the deviation from the standard area law ($\delta =0$). Based on black hole thermodynamics, we argue that the Barrow entropy should run (i.e., energy scale dependent), which is reasonable given that quantum gravitational corrections are expected to be important only in high energy regime. When applied to the Friedmann equation, we demonstrate the possibility that such a running Barrow entropy index could give rise to a dynamical effective dark energy, which is asymptotically positive and vanishing, but negative at the Big Bang. Such a sign switching dark energy could help to alleviate the Hubble tension. Other cosmological implications are discussed.

References in corpus (52)

• In the Realm of the Hubble tension $-$ a Review of Solutions
• Tensions between the Early and the Late Universe
• Horizon-scale tests of gravity theories and fundamental physics from the Event Horizon Telescope image of Sagittarius A${}^{\ast }$
• Varying constants, Gravitation and Cosmology
• Renormalization group improved black hole spacetimes
• The Area of a Rough Black Hole
• Hawking Radiation and Black Hole Thermodynamics
• Thermodynamics of an accelerated expanding universe
• Corrected Entropy-Area Relation and Modified Friedmann Equations
• Is the Hubble tension a hint of AdS phase around recombination?
• Friedmann Equations and Thermodynamics of Apparent Horizons
• Can Late Dark Energy Transitions Raise the Hubble constant?
• Early and late universe holographic cosmology from a new generalized entropy
• Revisiting a negative cosmological constant from low-redshift data
• Barrow entropic dark energy: A member of generalized holographic dark energy family
• Fractal properties of quantum spacetime
• Graduated dark energy: Observational hints of a spontaneous sign switch in the cosmological constant
• Big Bang Nucleosynthesis constraints on Barrow entropy
• Tension between the power spectrum of density perturbations measured on large and small scales
• Modified cosmology through spacetime thermodynamics and Barrow horizon entropy
• The generalized second law of thermodynamics with Barrow entropy
• Relaxing cosmological tensions with a sign switching cosmological constant
• Beyond $\Lambda$CDM with Low and High Redshift Data: Implications for Dark Energy
• Barrow Entropy Corrections to Friedmann Equations
• Dynamics of an Interacting Barrow Holographic Dark Energy Model and its Thermodynamic Implications
• Quantifying the $S_8$ tension with the Redshift Space Distortion data set
• Do cosmological observations allow a negative $\Lambda$?
• Prospecting Black Hole Thermodynamics with Fractional Quantum Mechanics
• Graviton fluctuations erase the cosmological constant
• $T_0$ censorship of early dark energy and AdS vacua
• Constraints on Barrow entropy from M87* and S2 star observations
• Barrow Entropy Cosmology: an observational approach with a hint of stability analysis
• Algebraic approach to quantum black holes: logarithmic corrections to black hole entropy
• Baryon asymmetry from Barrow entropy: theoretical predictions and observational constraints
• Asymptotically safe gravity as a scalar-tensor theory and its cosmological implications
• Vacuum Fluctuations and the Small Scale Structure of Spacetime
• Growth of Perturbations in Tsallis and Barrow Cosmology
• Gauge-Dependent Cosmological "Constant"
• Consistent early and late time cosmology from the RG flow of gravity
• Can varying the gravitational constant alleviate the tensions ?
• Running Newton Coupling, Scale Identification and Black Hole Thermodynamics
• ABC of multi-fractal spacetimes and fractional sea turtles
• Fractal Spacetimes in Stochastic Gravity? -- Views from Anomalous Diffusion and the Correlation Hierarchy
• Decaying Dark Energy in Higher-Dimensional Gravity
• Arrow of Time in String Theory
• Non-singular AdS-dS transitions in a landscape scenario
• Smooth Initial Conditions from Weak Gravity
• Scalar cosmological perturbations from inflationary black holes
• Cuscuta-Galileon cosmology: Dynamics, gravitational "constant"s and the Hubble Constant
• The cosmological constant and higher dimensional dilatation symmetry
• Solving the Cosmological Entropy Issue with a Higgs Dilaton
• On Effective Spacetime Dimension in the Hořava-Lifshitz Gravity