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Related papers: Non-Extensive Entropy and Power-Law Inflation: Imp…

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We derive non-flat cosmological models for two cases (i.e., dust and radiation) in the context of M{\o}ller's tetradic theory (MTT) of gravitation using the tetrad that creates the non-flat Friedmann-Robertson-Walker (FRW) metric. These two…

General Relativity and Quantum Cosmology · Physics 2022-04-21 G. G. L. Nashed , A. T. Shafeek

Recently, Tsallis, R\'{e}nyi and Sharma-Mitall and entropies have widely been used to study the gravitational and cosmological setups. We consider a flat FRW universe with linear interaction between dark energy and dark matter. We discuss…

General Physics · Physics 2019-01-08 M. Younas , Abdul Jawad , Saba Qummer , H. Moradpour , Shamaila Rani

We apply the first law of thermodynamics to the apparent horizon of the universe with the power-law corrected and non-extensive Tsallis entropies rather than the Bekenstein-Hawking one. We examine the cosmological properties in the two…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-14 Chao-Qiang Geng , Yan-Ting Hsu , Jhih-Rong Lu , Lu Yin

In spirit of the recently proposed four-parameter generalized entropy of apparent horizon, we investigate inflationary cosmology where the matter field inside of the horizon is dominated by a scalar field with a power law potential (i.e.,…

General Relativity and Quantum Cosmology · Physics 2023-12-22 Sergei D. Odintsov , Simone D'Onofrio , Tanmoy Paul

Experimental particle spectra can be successfully described by power-law tailed energy distributions characteristic to canonical equilibrium distributions associated to R\'enyi's or Tsallis' entropy formula - over a wide range of energies,…

Nuclear Theory · Physics 2013-06-27 T. S. Biró , E. Molnár

Here, we consider new nonadditive entropy of the apparent horizon $S_K=S_{BH}/(1+\gamma S_{BH})$ with $S_{BH}$ being the Bekenstein--Hawking entropy. This is an alternative of the R\'{e}nyi and Tsallis entropies, that allows us, by…

General Physics · Physics 2025-11-18 S. I. Kruglov

We study constraints on a number of patch inflationary models in noncommutative spacetime using a compilation of recent high-precision observational data. In particular, the four-dimensional General Relativistic (GR) case, the…

Astrophysics · Physics 2007-05-23 Gianluca Calcagni , Shinji Tsujikawa

We investigate a four-parameter entropic dark energy model in a spatially curved FLRW universe, based on a generalized entropy-area relation at the apparent horizon. While the proposed entropy function captures a broad class of…

General Relativity and Quantum Cosmology · Physics 2025-11-21 Davood Momeni

We show that the non-additivity relation of the Tsallis entropies in nonextensive statistical mechanics has a simple physical interpretation for systems with fluctuating temperature or fluctuating energy dissipation rate. We also show that…

Statistical Mechanics · Physics 2009-11-07 Christian Beck

We extend an alternative, phenomenological approach to inflation by means of an equation of state and a sound speed, both of them functions of the number of $e$-folds and four phenomenological parameters. This approach captures a number of…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-10 Stefano Gariazzo , Olga Mena , Hector Ramirez , Lotfi Boubekeur

In this paper, we investigate the validity of the so-called cosmic no-hair conjecture in the framework of anisotropic inflation models of non-canonical scalar fields non-minimally coupled to a two-form field. In particular, we focus on two…

General Relativity and Quantum Cosmology · Physics 2024-02-06 Tuyen M. Pham , Duy H. Nguyen , Tuan Q. Do , W. F. Kao

Dissipative processes cause collisionless plasmas in many systems to develop nonthermal particle distributions with broad power-law tails. The prevalence of power-law energy distributions in space/astrophysical observations and kinetic…

High Energy Astrophysical Phenomena · Physics 2022-07-06 Vladimir Zhdankin

In this paper, we propose a new method to calculate the mode functions in the noncommutative power-law inflation model. In this model, all the modes created when the stringy space-time uncertainty relation is satisfied are generated inside…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-02 Chao-Jun Feng , Xin-Zhou Li , Dao-Jun Liu

This paper studies the thermodynamic topology through the bulk-boundary and restricted phase space (RPS) frameworks. In bulk-boundary framework, we observe two topological charges $(\omega = +1, -1)$ concerning the non-extensive Barrow…

High Energy Physics - Theory · Physics 2025-12-24 Saeed Noori Gashti , Behnam Pourhassan , Izzet Sakalli

Most astrophysical plasmas are observed to have velocity distribution functions exhibiting non-Maxwellian suprathermal tails. The high energy particle populations are accurately represented by the family of kappa-distributions where the use…

Astrophysics · Physics 2009-11-07 Manfred P. Leubner

We propose a new entropy construct that generalizes the Tsallis, R\'enyi, Sharma-Mittal, Barrow, Kaniadakis, and Loop Quantum Gravity entropies and reduces to the Bekenstein-Hawking entropy in a certain limit. This proposal is applied to…

General Relativity and Quantum Cosmology · Physics 2022-01-10 Shin'ichi Nojiri , Sergei D. Odintsov , Valerio Faraoni

Power-law inflation with $a(t) \propto t^m$ is conceptually simple and predicts a scalar tilt $n_s = 1 - 2/m$ compatible with CMB data, but in four-dimensional Einstein gravity it typically yields a tensor-to-scalar ratio $r = 16/m$ that is…

General Relativity and Quantum Cosmology · Physics 2026-02-19 Daniel Oliveira , Seyed Rasouli , Joao Marto , Paulo Moniz

Recent cosmic microwave background (CMB) observations put strong constraints on the spatial curvature via estimation of the parameter $\Omega_k$ assuming an almost scale invariant primordial power spectrum. We study the evolution of the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-31 Béatrice Bonga , Brajesh Gupt , Nelson Yokomizo

We point out that by considering the Hawking-Bekenstein entropy of Schwarzschild black hole horizons as a non-extensive Tsallis entropy, its additive formal logarithm, coinciding with the Renyi entropy, generates an equation of state with…

High Energy Physics - Phenomenology · Physics 2010-11-16 Tamas S. Biro

We discuss the entropy and the size/homogeneity/horizon problems in power-law expanding universes with one scale initial conditions. We set the minimal scale $\Lambda = 10^{25}$ GeV at which a non-inflationary solution is possible and show…

High Energy Physics - Phenomenology · Physics 2009-01-07 Natalia Shuhmaher