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We show that Abe's general pseudoadditivity for entropy prescribed by thermal equilibrium in nonextensive systems holds not only for entropy, but also for energy. The application of this general pseudoadditivity to Tsallis entropy tells us…

Statistical Mechanics · Physics 2009-11-07 Qiuping A. Wang , Laurent Nivanen , Alain Le Mehaute , Michel Pezeril

Self-gravitating system are non-equilibrium a priory. A new approach is proposed, which employs a non-equilibrium statistical operator into account inhomogeneous distribution of particles and temperature. The method involves the saddle -…

Statistical Mechanics · Physics 2016-04-12 B. I. Lev

Within the Tsallis thermodynamics' framework, and using scaling properties of the entropy, we derive a generalization of the Gibbs-Duhem equation. The analysis suggests a transformation of variables that allows standard thermodynamics to be…

Statistical Mechanics · Physics 2009-11-07 Eduard Vives , Antoni Planes

In the paper we discuss equilibrium states of stars, using a simplified analytic model. A star is considered as self-graviting body of gas. We use a condition for the equilibrium state of the body in the form of a differential equation,…

General Physics · Physics 2015-04-23 Andrei Smirnov , Ricardo Max Menezes Oliveira

Astrophysical systems differ often in two points from classical thermodynamical systems: 1.) They are open and 2.) gravity is a dominant factor. Both modifies the homogeneous equilibrium structure, known from classical thermodynamics. In…

Astrophysics · Physics 2007-05-23 Daniel Huber

We develop a general formalism to determine the statistical equilibrium states of self-gravitating systems in general relativity and complete previous works on the subject. Our results are valid for an arbitrary form of entropy but, for…

General Relativity and Quantum Cosmology · Physics 2020-12-24 Pierre-Henri Chavanis

A study of the effects of non-extensivity on the modelling of atomic physics in hot dense plasmas is proposed within Tsallis' statistics. The electronic structure of the plasma is calculated through an average-atom model based on the…

Plasma Physics · Physics 2015-05-30 Jean-Christophe Pain , Denis Teychenné , Franck Gilleron

Quite general, analytical (both exact and approximate) forms for discrete probability distributions (PD's) that maximize Tsallis entropy for a fixed variance are here investigated. They apply, for instance, in a wide variety of scenarios in…

Statistical Mechanics · Physics 2009-11-11 C. Vignat , A. Plastino

We derive Tsallis entropy, Sq, from universal thermostat independence and obtain the functional form of the corresponding generalized entropy-probability relation. Our result for finite thermostats interprets thermodynamically the subsystem…

High Energy Physics - Phenomenology · Physics 2014-05-19 T. S. Biró , G. G. Barnaföldi , P. Ván

Euler turbulence has been experimentally observed to relax to a metaequilibrium state that does not maximize the Boltzmann entropy, but rather seems to minimize enstrophy. We show that a recent generalization of thermodynamics and…

chao-dyn · Physics 2016-08-31 Bruce M. Boghosian

We consider nonequilibrium systems with complex dynamics in stationary states with large fluctuations of intensive quantities (e.g. the temperature, chemical potential, or energy dissipation) on long time scales. Depending on the…

Statistical Mechanics · Physics 2009-11-07 C. Beck , E. G. D. Cohen

Important gaps remain in our understanding of the thermodynamics and statistical physics of self-gravitating systems. Using mean field theory, here we investigate the equilibrium properties of several spherically symmetric model systems…

Statistical Mechanics · Physics 2009-10-31 Peter J. Klinko , Bruce N. Miller

We propose an approach to find out when a self-gravitating system is in a quasi-equilibrium state. This approach is based on a comparison between two quantities identifying behavior of the system: a measure of interactions intensity and the…

High Energy Physics - Theory · Physics 2022-07-26 Azizollah Azizi , Amir A. Khodahami

The thermodynamic stability condition (TSC) of Tsallis' entropy is revisited. As Ramshaw [Phys. Lett. A {\bf 198} (1995) 119] has already pointed out, the concavity of Tsallis' entropy with respect to the internal energy is not sufficient…

Statistical Mechanics · Physics 2009-11-07 T. Wada

(abbreviated) The statistical mechanics of self-gravitating systems is a long-held puzzle. In this work, we employ a phenomenological entropy form of ideal gas, first proposed by White & Narayan, to revisit this issue. By calculating the…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-09 Ping He , Dong-Biao Kang

Real physical systems are often maintained off equilibrium by energy or matter flows. If these systems are far from equilibrium then the thermodynamical branch become unstable and fluctuations can lead them to other more stable states.…

Astrophysics · Physics 2007-05-23 Daniel Huber

The Bekenstein-Hawking entropy suggests that thermodynamics is an intrinsic ingredient of gravity. Here, we explore the idea that requirements of thermodynamic consistency could determine the gravitational entropy in other set-ups. We…

General Relativity and Quantum Cosmology · Physics 2011-12-23 Charis Anastopoulos , Ntina Savvidou

We address the generalized thermodynamics and the collapse of a system of self-gravitating Langevin particles exhibiting anomalous diffusion in a space of dimension D. The equilibrium states correspond to polytropic distributions. The index…

Statistical Mechanics · Physics 2009-11-10 Pierre-Henri Chavanis , Clement Sire

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

Many complex systems are characterized by non-Boltzmann distribution functions of their statistical variables. If one wants to -- justified or not -- hold on to the maximum entropy principle for complex statistical systems (non-Boltzmann)…

Statistical Mechanics · Physics 2009-11-13 Stefan Thurner , Rudolf Hanel