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Related papers: Baryogenesis in non-extensive Tsallis Cosmology

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We provide the most stringent constraint to date on possible deviations from the usually-assumed Maxwell-Boltzmann (MB) velocity distribution for nuclei in the Big-Bang plasma. The impact of non-extensive Tsallis statistics on thermonuclear…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-20 S. Q. Hou , J. J. He , A. Parikh , K. Daid , C. Bertulani

In this study the q-statistics of Tsallis theory is testified in various complex physical systems. Especially the Tsallis q-triplet is estimated for space plasmas atmospheric dynamics and seismogenesis as well as for the brain and cardiac…

It is pointed out that the constraint to be imposed to the maximization of the entropy for processes outside the class of thermodynamical systems, is generally not well defined. In fact, any probability distribution can be derived from…

Statistical Mechanics · Physics 2009-11-10 Damian H. Zanette , Marcelo M. Montemurro

The baryogenesis presents the theoretical mechanism that describes the matter-antimatter asymmetry in the history of early universe. In this work, we investigate the gravitational baryogenesis phenomena in the frameworks of $f(T, T_G)$…

General Relativity and Quantum Cosmology · Physics 2020-09-29 Nadeem Azhar , Abdul Jawad , Shamaila Rani

The gravitational baryogenesis plays an important role in the study of the baryon asymmetry. However, the original mechanism of gravitational baryogenesis in the radiation dominated era leads to the asymmetry factor $\eta$ is equal to zero,…

General Relativity and Quantum Cosmology · Physics 2022-07-12 Zhong-Wen Feng , Xia Zhou , Shi-Qi Zhou

In this paper, we first obtain the energy density by the approach of the new agegraphic dark energy model, and then the $f(T,B)$ gravity model is studied as an alternative to the dark energy in a viscous fluid by flat-FRW background, in…

General Relativity and Quantum Cosmology · Physics 2020-06-17 A. Pourbagher , Alireza Amani

Considering galaxies as self - gravitating systems of many collisionless particles allows to use methods of statistical mechanics inferring the distribution function of these stellar systems. Actually, the long range nature of the…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-04 V. F. Cardone , M. P. Leubner , A. Del Popolo

The forms of Euler and Gibbs-Duhem relations discussed in thermodynamics of extensive systems are shown to hold also for nonextensive systems with long-range interactions with a novel interpretation of entities appearing therein. In this…

Statistical Mechanics · Physics 2009-11-10 Sumiyoshi Abe , A. K. Rajagopal

According to the thermodynamics-gravity conjecture, any modification to the entropy expression leads to the modified cosmological field equations. Based on this, we investigate the cosmological consequences of the modified Friedmann…

General Relativity and Quantum Cosmology · Physics 2024-05-24 Esmaeil Ebrahimi , Ahmad Sheykhi

The problem of temperature in nonextensive statistical mechanics is studied. Considering the first law of thermodynamics and a "quasi-reversible process", it is shown that the Tsallis entropy becomes the Clausius entropy if the inverse of…

Statistical Mechanics · Physics 2009-11-11 Sumiyoshi Abe

An analysis of the thermodynamic behavior of quantum systems can be performed from a geometrical perspective investigating the structure of the state space. We have developed such an analysis for nonextensive thermostatistical frameworks,…

Statistical Mechanics · Physics 2009-11-11 M. Portesi , A. Plastino , F. Pennini

For a general, associative addition rule defining a non-extensive thermodynamics we construct the strict monotonic function, which transforms it to an additive quantity. We investigate the evolution of one-particle distributions in the…

High Energy Physics - Phenomenology · Physics 2009-11-11 T. S. Biro , G. Purcsel

A unified presentation of the perturbation and variational methods for the generalized statistical mechanics based on Tsallis entropy is given here. In the case of the variational method, the Bogoliubov inequality is generalized in a very…

Statistical Mechanics · Physics 2009-10-31 E. K. Lenzi , L. C. Malacarne , R. S. Mendes

We establish new constraints on $f(T)$ gravity models by using cosmological data. In particular, we investigate the restrictions given by the gas mass fraction measurements of galaxy clusters and transversal BAO data. Both data sets are…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-28 F. B. M. dos Santos , J. E. Gonzalez , R. Silva

This work explores the influence of viscous fluids on cosmological dynamics within the framework of General Relativity. We introduce a novel time-dependent parametrization for the bulk viscosity coefficient, given by \(\zeta = \zeta_0 (t -…

General Relativity and Quantum Cosmology · Physics 2025-04-30 Rajdeep Mazumdar , Mrinnoy M. Gohain , Kalyan Bhuyan

In this study, we propose an extension of general relativity inspired by the van der Waals equation of state, incorporating non-ideal thermodynamic effects into the gravitational sector. Our approach is based on the thermodynamic…

General Relativity and Quantum Cosmology · Physics 2026-04-23 H. R. Fazlollahi

Recently, the R\'{e}nyi and Tsallis generalized entropies have extensively been used in order to study various cosmological and gravitational setups. Here, using a special type of generalized entropy, a generalization of both the R\'{e}nyi…

General Relativity and Quantum Cosmology · Physics 2018-04-05 A. Sayahian Jahromi , S. A. Moosavi , H. Moradpour , J. P. Morais Graça , I. P. Lobo , I. G. Salako , A. Jawad

Gravitational baryogenesis is one of the mechanisms which help us to explore more about our early universe, especially baryon-anti-baryon asymmetry. As we know, modified theories of gravity are very successful in describing the present…

General Relativity and Quantum Cosmology · Physics 2023-05-23 Sai Swagat Mishra , Sanjay Mandal , P. K. Sahoo

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 the context of Brans-Dicke scalar tensor theory of gravitation, the cosmological Friedmann equation which relates the expansion rate $H$ of the universe to the various fractions of energy density is analyzed rigorously. It is shown that…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. Arik , M. C. Calik , M. B. Sheftel