We argue that complex systems must possess long range correlations and illustrate this idea on the example of the mean field spin glass model. Defined on the complete graph, this model has no genuine concept of distance, but the long range character of correlations is translated into a broad distribution of the spin-spin correlation coefficients for almost all realizations of the random couplings. When we sample the whole phase space we find that this distribution is indeed so broad that at low temperatures it essentially becomes uniform, with all possible correlation values appearing with the same probability. The distribution of correlations inside a single phase space valley is also studied and found to be much narrower.
Large random correlations in individual mean field spin glass samples / Alain, Billoire; Imre, Kondor; Jovanka, Lukic; Marinari, Vincenzo. - In: JOURNAL OF STATISTICAL MECHANICS: THEORY AND EXPERIMENT. - ISSN 1742-5468. - P02009:2(2011), pp. 1-13. [10.1088/1742-5468/2011/02/p02009]
Large random correlations in individual mean field spin glass samples
MARINARI, Vincenzo
2011
Abstract
We argue that complex systems must possess long range correlations and illustrate this idea on the example of the mean field spin glass model. Defined on the complete graph, this model has no genuine concept of distance, but the long range character of correlations is translated into a broad distribution of the spin-spin correlation coefficients for almost all realizations of the random couplings. When we sample the whole phase space we find that this distribution is indeed so broad that at low temperatures it essentially becomes uniform, with all possible correlation values appearing with the same probability. The distribution of correlations inside a single phase space valley is also studied and found to be much narrower.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.