To: Stan who wrote (1197 ) 7/22/2014 5:03:28 AM From: S. maltophilia 1 RecommendationRecommended By R2O
Read Replies (1) | Respond to of 1203 Following the links, I found some clarification The concept of extensivity is introduced early in most textbooks on thermodynamics and statistical physics. The requirement that the entropy be additive establishes the form of the Boltzmann-Gibbs distribution via a straightforward argument. Recently, Tsallis [1] has proposed a generalization of Boltzmann-Gibbs thermostatistics by introducing a family of generalized entropy functionals with a single parameter q . The proposed generalization is best described by the following two axioms: Axiom 1 The entropy functional associated with a probability distribution f(z ) is Axiom 2 The experimentally measured value of a phase function g(z ) is given by the q-expectation value, From the first axiom, we note that Sq [f ] reduces to the Boltzmann-Gibbs entropy in the limit as q ® 1, We first review the construction of the canonical ensemble distribution function using the generalized thermostatistics [1]. We maximize Sq [f ], given by Eq. (1), subject to the preservation of various linear global functionals of f (z ). By Tsallis' second postulate, Eq. (2), these are given by where the index i ranges from 1 to the number of conserved quantities n . We are thus led to the variational principle, where the li 's are Lagrange multipliers. It is an elementary exercise to verify that this yields the equilibrium distribution function The n constants li are then determined by the n Eqs. (4) which may be written In passing, we note that a very recently proposed modification to Tsallis' second axiom [16] would normalize the q -expectation values as follows: <g>