The fluctuation-dissipation relation: how does one compare correlation functions and responses? Export

@article{citeulike:5152602, abstract = {We discuss the well known Einstein and the Kubo fluctuation-dissipation relations (FDRs) in the wider framework of a generalized FDR for systems with a stationary probability distribution. A multivariate linear Langevin model, which includes dynamics with memory, is used as a treatable example to show how the usual relations are recovered only in particular cases. This study brings to the fore the ambiguities of a check of the FDR done without knowing the significant degrees of freedom and their coupling. An analogous scenario emerges in the dynamics of diluted shaken granular media. There, the correlation between position and velocity of particles, due to spatial inhomogeneities, induces violation of usual FDRs. The search for the appropriate correlation function which could restore the FDR can be more insightful than a definition of 'non-equilibrium' or 'effective temperatures'.}, author = {Villamaina, D. and Baldassarri, A. and Puglisi, A. and Vulpiani, A.}, citeulike-article-id = {5152602}, citeulike-linkout-0 = {http://dx.doi.org/10.1088/1742-5468/2009/07/P07024}, doi = {10.1088/1742-5468/2009/07/P07024}, journal = {Journal of Statistical Mechanics: Theory and Experiment}, keywords = {fdt}, number = {07}, pages = {P07024+}, posted-at = {2009-07-15 00:54:15}, priority = {2}, title = {The fluctuation-dissipation relation: how does one compare correlation functions and responses?}, url = {http://dx.doi.org/10.1088/1742-5468/2009/07/P07024}, volume = {2009}, year = {2009} }

TY - JOUR ID - citeulike:5152602 L3 - citeulike-article-id:5152602 N2 - We discuss the well known Einstein and the Kubo fluctuation-dissipation relations (FDRs) in the wider framework of a generalized FDR for systems with a stationary probability distribution. A multivariate linear Langevin model, which includes dynamics with memory, is used as a treatable example to show how the usual relations are recovered only in particular cases. This study brings to the fore the ambiguities of a check of the FDR done without knowing the significant degrees of freedom and their coupling. An analogous scenario emerges in the dynamics of diluted shaken granular media. There, the correlation between position and velocity of particles, due to spatial inhomogeneities, induces violation of usual FDRs. The search for the appropriate correlation function which could restore the FDR can be more insightful than a definition of 'non-equilibrium' or 'effective temperatures'. IS - 07 JF - Journal of Statistical Mechanics: Theory and Experiment TI - The fluctuation-dissipation relation: how does one compare correlation functions and responses? VL - 2009 SP - P07024 KW - fdt AU - Villamaina, D AU - Baldassarri, A AU - Puglisi, A AU - Vulpiani, A PY - 2009/// UR - http://dx.doi.org/10.1088/1742-5468/2009/07/P07024 ER -