Entropy

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Open AccessArticle

A Universal Framework for Analysis of Self-Replication Phenomena

by Bryant Adams and Hod Lipson

Entropy 2009, 11(2), 295-325; https://doi.org/10.3390/e11020295 - 22 Jun 2009

Cited by 7 | Viewed by 6946

In this paper, we propose definitions for a general, domain-independent concept of replicability and specifically focus on the notion of self-replication. We argue that selfreplication should not be viewed as a binary property of a system, but rather as a continuously valued property [...] Read more.

In this paper, we propose definitions for a general, domain-independent concept of replicability and specifically focus on the notion of self-replication. We argue that selfreplication should not be viewed as a binary property of a system, but rather as a continuously valued property of the interaction between a system and its environment. This property, selfreplicability, represents the effect of the presence of a system upon the future presence of similar systems. We demonstrate both analytical and computational analysis of self-replicability for four distinct systems involving both discrete and continuous, formal and physical behaviors. Full article

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183 KiB

Open AccessArticle

Non-Extensivity of the Configurational Density Distribution in the Classical Microcanonical Ensemble

by Jan Naudts and Maarten Baeten

Entropy 2009, 11(2), 285-294; https://doi.org/10.3390/e11020285 - 11 Jun 2009

Cited by 7 | Viewed by 8887

Abstract

We show that the configurational probability distribution of a classical gas always belongs to the q-exponential family. One of the consequences of this observation is that the thermodynamics of the configurational subsystem is uniquely determined up to a scaling function. As an example [...] Read more.

We show that the configurational probability distribution of a classical gas always belongs to the q-exponential family. One of the consequences of this observation is that the thermodynamics of the configurational subsystem is uniquely determined up to a scaling function. As an example we consider a system of non-interacting harmonic oscillators. In this example, the scaling function can be determined from the requirement that in the limit of large systems the microcanonical temperature of the configurational subsystem should coincide with that of the canonical ensemble. The result suggests that R´enyi’s entropy function is the relevant one rather than that of Tsallis. Full article

241 KiB

Open AccessArticle

The Topological Pressure of Linear Cellular Automata

by Jung-Chao Ban and Chih-Hung Chang

Entropy 2009, 11(2), 271-284; https://doi.org/10.3390/e11020271 - 11 May 2009

Cited by 6 | Viewed by 8606

Abstract

This elucidation studies ergodicity and equilibrium measures for additive cellular automata with prime states. Additive cellular automata are ergodic with respect to Bernoulli measure unless it is either an identity map or constant. The formulae of measure-theoretic and topological entropies can be expressed [...] Read more.

This elucidation studies ergodicity and equilibrium measures for additive cellular automata with prime states. Additive cellular automata are ergodic with respect to Bernoulli measure unless it is either an identity map or constant. The formulae of measure-theoretic and topological entropies can be expressed in closed forms and the topological pressure is demonstrated explicitly for potential functions that depend on finitely many coordinates. According to these results, Parry measure is inferred to be an equilibrium measure. Full article

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Open AccessArticle

Generalised Entropy of Curves for the Analysis and Classification of Dynamical Systems

by Aldo Balestrino, Andrea Caiti and Emanuele Crisostomi

Entropy 2009, 11(2), 249-270; https://doi.org/10.3390/e11020249 - 29 Apr 2009

Cited by 13 | Viewed by 8394

Abstract

This paper provides a new approach for the analysis and eventually the classification of dynamical systems. The objective is pursued by extending the concept of the entropy of plane curves, first introduced within the theory of the thermodynamics of plane curves, to Rn [...] Read more.

This paper provides a new approach for the analysis and eventually the classification of dynamical systems. The objective is pursued by extending the concept of the entropy of plane curves, first introduced within the theory of the thermodynamics of plane curves, to Rn space. Such a generalised entropy of a curve is used to evaluate curves that are obtained by connecting several points in the phase space. As the points change their coordinates according to the equations of a dynamical system, the entropy of the curve connecting them is used to infer the behaviour of the underlying dynamics. According to the proposed method all linear dynamical systems evolve at constant zero entropy, while higher asymptotic values characterise nonlinear systems. The approach proves to be particularly efficient when applied to chaotic systems, in which case it has common features with other classic approaches. Performances of the proposed method are tested over several benchmark problems. Full article

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181 KiB

Open AccessArticle

Particle Indistinguishability Symmetry within a Field Theory. Entropic Effects

by Dung Di Caprio and Jean Pierre Badiali

Entropy 2009, 11(2), 238-248; https://doi.org/10.3390/e11020238 - 21 Apr 2009

Cited by 3 | Viewed by 8675

Abstract

In this paper, we briefly discuss a field theory approach of classical statistical mechanics. We show how an essentially entropic functional accounts for fundamental symmetries related to quantum mechanical properties which hold out in the classical limit of the quantum description. Within this [...] Read more.

In this paper, we briefly discuss a field theory approach of classical statistical mechanics. We show how an essentially entropic functional accounts for fundamental symmetries related to quantum mechanical properties which hold out in the classical limit of the quantum description. Within this framework, energetic and entropic properties are treated at equal level. Based on a series of examples on electrolytes, we illustrate how this framework gives simple interpretations where entropic fluctuations of anions and cations compete with the energetic properties related to the interaction potential. Full article

(This article belongs to the Special Issue Symmetry and Entropy)

563 KiB

Open AccessArticle

Maximum Entropy on Compact Groups

by Peter Harremoës

Entropy 2009, 11(2), 222-237; https://doi.org/10.3390/e11020222 - 01 Apr 2009

Cited by 10 | Viewed by 7751

Abstract

In a compact group the Haar probability measure plays the role of uniform distribution. The entropy and rate distortion theory for this uniform distribution is studied. New results and simplified proofs on convergence of convolutions on compact groups are presented and they can [...] Read more.

In a compact group the Haar probability measure plays the role of uniform distribution. The entropy and rate distortion theory for this uniform distribution is studied. New results and simplified proofs on convergence of convolutions on compact groups are presented and they can be formulated as entropy increases to its maximum. Information theoretic techniques and Markov chains play a crucial role. The convergence results are also formulated via rate distortion functions. The rate of convergence is shown to be exponential. Full article

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Entropy, Volume 11, Issue 2 (June 2009) – 6 articles , Pages 222-325

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