%0 Book Section %1 statphys23_0748 %A Bertin, E. %A Martens, K. %A Dauchot, O. %A Droz, M. %B Abstract Book of the XXIII IUPAP International Conference on Statistical Physics %C Genova, Italy %D 2007 %E Pietronero, Luciano %E Loreto, Vittorio %E Zapperi, Stefano %K equilibrium intensive out parameters states statphys23 steady thermodynamic topic-3 %T Intensive thermodynamic parameters in nonequilibrium systems %U http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=748 %X Considering a broad class of steady-state nonequilibrium systems for which some additive quantities are conserved by the dynamics, we introduce from a statistical approach intensive thermodynamic parameters (ITPs) conjugated to the conserved quantities. This definition does not require any detailed balance relation to be fulfilled. Rather, the system must satisfy a general additivity property, which holds in most of the models usually considered in the literature, including those described by a matrix product ansatz with finite matrices. Note that the systems considered here are out of equilibrium not due to the presence of gradients imposed, for instance, by boundary reservoirs, but because of the breaking of microreversibility (that is, time-reversal invariance) at the level of the microscopic dynamics in the bulk.\\ The main property of these ITPs is to take equal values in two subsystems, making them a powerful tool to describe nonequilibrium phase coexistence, as illustrated on different models.\\ We then discuss the issue of the equalization of ITPs when two different systems are put into contact. Although the proposed generalization of ITPs appears to be rather natural, it turns out that nontrivial problems arise as soon as systems with different dynamics are put into contact. This issue is essential if one wants to measure an ITP using a small auxiliary system — just like temperature is measured with a thermometer — and points at one of the main difficulties of nonequilibrium statistical mechanics.\\ Finally, an efficient alternative determination, based on the measure of fluctuations, is also proposed and illustrated.

@incollection{statphys23_0748, abstract = {Considering a broad class of steady-state nonequilibrium systems for which some additive quantities are conserved by the dynamics, we introduce from a statistical approach intensive thermodynamic parameters (ITPs) conjugated to the conserved quantities. This definition does not require any detailed balance relation to be fulfilled. Rather, the system must satisfy a general additivity property, which holds in most of the models usually considered in the literature, including those described by a matrix product ansatz with finite matrices. Note that the systems considered here are out of equilibrium not due to the presence of gradients imposed, for instance, by boundary reservoirs, but because of the breaking of microreversibility (that is, time-reversal invariance) at the level of the microscopic dynamics in the bulk.\\ The main property of these ITPs is to take equal values in two subsystems, making them a powerful tool to describe nonequilibrium phase coexistence, as illustrated on different models.\\ We then discuss the issue of the equalization of ITPs when two different systems are put into contact. Although the proposed generalization of ITPs appears to be rather natural, it turns out that nontrivial problems arise as soon as systems with different dynamics are put into contact. This issue is essential if one wants to measure an ITP using a small auxiliary system — just like temperature is measured with a thermometer — and points at one of the main difficulties of nonequilibrium statistical mechanics.\\ Finally, an efficient alternative determination, based on the measure of fluctuations, is also proposed and illustrated.}, added-at = {2007-06-20T10:16:09.000+0200}, address = {Genova, Italy}, author = {Bertin, E. and Martens, K. and Dauchot, O. and Droz, M.}, biburl = {https://www.bibsonomy.org/bibtex/256fe9396914fba978bda08fbbc4e8fd9/statphys23}, booktitle = {Abstract Book of the XXIII IUPAP International Conference on Statistical Physics}, editor = {Pietronero, Luciano and Loreto, Vittorio and Zapperi, Stefano}, interhash = {9c2b3feec7d6b231a9537770b1d5800f}, intrahash = {56fe9396914fba978bda08fbbc4e8fd9}, keywords = {equilibrium intensive out parameters states statphys23 steady thermodynamic topic-3}, month = {9-13 July}, timestamp = {2007-06-20T10:16:28.000+0200}, title = {Intensive thermodynamic parameters in nonequilibrium systems}, url = {http://st23.statphys23.org/webservices/abstract/preview_pop.php?ID_PAPER=748}, year = 2007 }