Constraints on Rényi Entropy through Primordial Big-Bang Nucleosynthesis and Baryogenesis
arXiv:2507.14250 · doi:10.1016/j.dark.2026.102385
Abstract
The Rényi entropy, a one-parameter generalization of Boltzmann-Gibbs entropy, offers a promising framework for probing quantum gravitational effects in cosmology. By modifying the entropy-area relation of the apparent horizon, Rényi entropy can alter the expansion dynamics of the early universe, with potential implications for Big-Bang Nucleosynthesis. In this work, we derive the modified Friedmann equations within the Rényi entropy paradigm and investigate their impact on the primordial abundances of light elements Deuterium (), Helium-4 (), Lithium-7 () and baryogenesis. Using observational constraints from Planck, primordial abundance data and observational data on baryogenesis, we put stringent bounds on the Rényi parameter. Furthermore, we explore whether Rényi entropy corrections could mitigate the long-standing Lithium discrepancy. This study provides the first systematic constraints on Rényi cosmology from BBN and highlights the role of nonextensive thermodynamics in early-universe physics. Our analysis shows that the obtained ranges for the Rényi parameter exhibit a overlap for the Helium-4 and Deuterium, but this overlapping region-despite a small discrepancy-is inconsistent with the range obtained from Lithium-7. This small mismatch between the ranges raises the possibility of alleviating the \textit{Lithium Problem} in the modified cosmology scenarios. Furthermore, we present the relationship between the cosmic time and temperature within the framework of Rényi cosmology. We observe that an increase in the Rényi parameter increase the temperature of the early universe.
arXiv comment13 pages, 5 figures, Accepted by Phys. Dark Univ
References in corpus (38)
- Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Sky Maps, Systematic Errors, and Basic Results
- First Law of Thermodynamics and Friedmann Equations of Friedmann-Robertson-Walker Universe
- Recent Progress in Baryogenesis
- Statistical mechanics in the context of special relativity
- Unified first law of black-hole dynamics and relativistic thermodynamics
- Primordial Nucleosynthesis in the Precision Cosmology Era
- Thermodynamic Behavior of Friedmann Equation at Apparent Horizon of FRW Universe
- The Area of a Rough Black Hole
- Matter and Antimatter in the Universe
- Statistical mechanics in the context of special relativity II
- Big-Bang Nucleosynthesis After Planck
- Dynamic black-hole entropy
- Gravitational Baryogenesis
- Standard Big-Bang Nucleosynthesis up to CNO with an improved extended nuclear network
- Modified cosmology from extended entropy with varying exponent
- Early and late universe holographic cosmology from a new generalized entropy
- Modified Friedmann Equations from Tsallis Entropy
- Big Bang Nucleosynthesis constraints on Barrow entropy
- Kaniadakis holographic dark energy and cosmology
- Cosmological model from the holographic equipartition law with a modified Rényi entropy
- Modified cosmology through spacetime thermodynamics and Barrow horizon entropy
- Entropic Corrections to Friedmann Equations
- Accelerated cosmos in a non-extensive setup
- Barrow Entropy Corrections to Friedmann Equations
- BBN For Pedestrians
- gravitational baryogenesis
- Primordial Nucleosynthesis with CMB Inputs: Probing the Early Universe and Light Element Astrophysics
- Modified cosmology through Kaniadakis horizon entropy
- Neutrino coupling to cosmological background: A review on gravitational Baryo/Leptogenesis
- Baryogenesis, 30 Years after
- Modified cosmology through Barrow entropy
- Baryon Asymmetry from the Generalized Uncertainty Principle
- Big Bang Nucleosynthesis and Entropy Evolution in Gravity
- Corrections to Friedmann equations inspired by Kaniadakis entropy
- Primordial Big Bang Nucleosynthesis and Generalized Uncertainty Principle
- Barrow Cosmology and Big-Bang Nucleosynthesis
- Constraints on Tsallis Cosmology from Big Bang Nucleosynthesis and Dark Matter Freeze-out
- Observational constraints and dynamical analysis of Kaniadakis horizon-entropy cosmology