Ideal gas provides q-entropy

A mathematical procedure is suggested to obtain deformed entropy formulas of type K(S_K) = sum_i P_i K(-ln P_i), by requiring zero mutual K(S_K)-information between a finite subsystem and a finite reservoir. The use of this method is first demonstrated on the ideal gas equation of state with finite constant heat capacity, C, where it delivers the Renyi and Tsallis formulas. A novel interpretation of the qstar = 2-q duality arises from the comparison of canonical subsystem and total microcanonical partition approaches. Finally a new, generalized deformed entropy formula is constructed for the linear relation C(S) = C_0 + C_1 S.Comment: more introduction, citations and derivation in v3; accepted in Physica

Non-Extensive Approach to Quark Matter

We review the idea of generating non-extensive stationary distributions based on abstract composition rules for the subsystem energies, in particular the relativistic generalized Boltzmann equation method. The thermodynamical behavior of such systems is investigated and hadron spectra stemming from relativistic heavy ion collisions are calculated by assuming quark coalescence.Comment: Review prepared for The European Physical Journal A - Hadrons and Nuclei, as part of a review block about applications of non-extensive thermodynamics in high-energy phenomen

Monopoles in Real Time for Classical U(1) Gauge Field Theory

U(1) gauge fields are decomposed into a monopole and photon part across the phase transition from the confinement to the Coulomb phase. We analyze the leading Lyapunov exponents of such gauge field configurations on the lattice which are initialized by quantum Monte Carlo simulations. We observe that the monopole field carries the same Lyapunov exponent as the original U(1) field. As a long awaited result, we show that monopoles are created and annihilated in pairs as a function of real time in excess to a fixed average monopole number.Comment: Contribution to the "International Conference on Color Confinement and Hadrons in Quantum Chromodynamics - Confinement 2003" (Tokyo, Japan, 2003-07-21 -- 2003-07-24); 5 pages; 6 figure

Entropy Production During Hadronization of a Quark-Gluon Plasma

We revisit the physical pictures for the hadronization of quark-gluon plasma, concentrating on the problem of entropy production during processes where the number of degrees of freedom is seemingly reduced due to color confinement. Based on observations on Regge trajectories we propose not having an infinite tower of hadronic resonances. We discuss possible entropy production mechanisms far from equilibrium in terms of stochastic dynamics.Comment: Submitted to EPJ A Topical Issue on "Frontiers in nuclear, heavy ion and strong field physics", in memoriam Walter Greine