×

Metastates in disordered mean-field models: Random field and Hopfield models. (English) Zbl 0924.60092

Statistical mechanics of disordered systems deals with the construction of Gibbs probability measures that are themselves random variables on some probability space describing the ‘quenched disorder’, i.e. typically the random interactions of the system. On of the main issues is to describe the thermodynamic limit, i.e. the limiting measures obtained by taking the system size to infinity. In the random case, what is the most appropriate probabilistic setting to formulate this problem? This important and long neglected issue has been addressed in a series of papers by Ch. Newman and D. Stein [see, e.g., Ch. M. Newman, “Topics in disordered systems” (1997; Zbl 0897.60093)] who proposed two concepts of ‘metastates’ (probability states on the space of Gibbs measures) as appropriate candidates to study the infinite volume limits of disordered systems. In the present paper the author gives explicit constructions of the two types of metastates proposed in the simplest examples: the random field version of the Curie-Weiss model, and the Hopfield model with finitely many patterns. It turns out that already in this small class of models, a variety of behaviours can be found, and a lot of insight in the general concept can be gained (the author even exhibits a counterexample to a conjecture of Newman and Stein concerning the relation of their two types of metastates). The reviewer would recommend reading of this paper to anyone interested in understanding the metastate concept.
Reviewer: A.Bovier (Berlin)

MSC:

60K40 Other physical applications of random processes
82B44 Disordered systems (random Ising models, random Schrödinger operators, etc.) in equilibrium statistical mechanics
60G57 Random measures

Citations:

Zbl 0897.60093
Full Text: DOI

References:

[1] Amaro de Matos, J. M. G.; Patrick, A. E.; Zagrebnov, V. A., Random Infinite-Volume Gibbs States for the Curie-Weiss Random Field Ising Model, J. Stat. Phys., 66, 139-164 (1992) · Zbl 0925.60127 · doi:10.1007/BF01060064
[2] Amaro de Matos, J. M. G.; Perez, J. F., Fluctuations in the Curie-Weiss Version of the Random Field Ising Model, J. Stat. Phys., 62, 587-608 (1990) · Zbl 0739.60090 · doi:10.1007/BF01017975
[3] Aizenman, M.; Wehr, J., Rounding Effects of Quenched Randomness on First-Order Phase Transitions, Comm. Math. Phys., 130, 489-528 (1990) · Zbl 0714.60090 · doi:10.1007/BF02096933
[4] A. Bovier and V. Gayrard, The retrieval phase of the Hopfield model: A rigorous analysis of the overlap distribution, to appear inProb. Theor. Rel. Fields (1995). · Zbl 0866.60085
[5] A. Bovier and V. Gayrard, Hopfield models as a generalized random mean field model, WIAS preprint 253, Berlin (1996), to appear in “Mathematics of spin glasses and neural networks,” A. Bovier and P. Picco, eds., “Progress in Probability,” Birkhäuser (1997). · Zbl 0899.60087
[6] Bovier, A.; Gayrard, V.; Picco, P., Gibbs states of the Hopfield model in the regime of perfect memory, Prob. Theor. Rel. Fields, 100, 329-363 (1994) · Zbl 0810.60094 · doi:10.1007/BF01193704
[7] Comets, F., Large Deviation Estimates for a Conditional Probability Distribution. Applications to Random Interaction Gibbs Measures, Prob. Th. Rel. Fields, 80, 407-432 (1989) · Zbl 0638.60037 · doi:10.1007/BF01794432
[8] Deuschel, J.-D.; Stroock, D. W., Large Deviations, Pure and Applied Mathematics (1989), Boston: Academic Press, Boston · Zbl 0705.60029
[9] Dembo, A.; Zeitouni, O., Large Deviations Techniques (1993), Boston, London: Jones and Bartlett, Boston, London · Zbl 0793.60030
[10] R. S. Ellis, Entropy,Large Deviations, and Statistical Mechanics, Grundlehren der mathematischen Wissenschaften, vol. 271, Springer, New York.
[11] Feller, W., An Introduction yo Probability Theory and its Applications (1966), New York, London, Sidney: Wiley, New York, London, Sidney · Zbl 0138.10207
[12] Gentz, B., An almost sure Central Limit Theorem for the overlap parameters in the Hopfield model, Stochastic Process. Appl., 62, 2, 243-262 (1996) · Zbl 0863.60019 · doi:10.1016/0304-4149(96)00055-5
[13] Georgii, H. O., Gibbs measures and phase transitions, Studies in mathematics, vol. 9 (1988), Berlin, New York: de Gruyter, Berlin, New York · Zbl 0657.60122
[14] Hopfield, J. J., Neural networks and physical systems with emergent collective computational abilities, Proc. Natl. Acad. Sci. USA, 79, 2554-2558 (1982) · Zbl 1369.92007 · doi:10.1073/pnas.79.8.2554
[15] Ledrappier, F., Pressure and Variational Principle for Random Ising Model, Comm. Math. Phys., 56, 297-302 (1977) · Zbl 0367.60116 · doi:10.1007/BF01614214
[16] Lewis, J. T.; Pfister, C. E.; Sullivan, W. G., Entropy, Concentration of Probability and Conditional Limit Theorems, Markov Proc. Rel. Felds, 1, 319-386 (1995) · Zbl 0901.60014
[17] C. M. Newman,Topics in Disordered Systems, to appear in “ETH Lecture Notes Series,” Birkhäuser (1996). · Zbl 0897.60093
[18] Newman, C. M.; Stein, D. L.; Boccara, Goles; Martinez, Picco, Chaotic Size Dependence in Spin Glasses, inCellular Automata and Cooperative Systems, Nato ASI Series C Vol. 396 (1993), Dordrecht: Kluwer, Dordrecht
[19] Newman, C. M.; Stein, D. L., Non-Mean Field Behavior in realistic Spin glasses, Phys. Rev. Lett., 76, 3, 515-515 (1996) · doi:10.1103/PhysRevLett.76.515
[20] Newman, C. M.; Stein, D. L., Spatial Inhomogeneity and thermodynamic chaos, Phys. Rev. Lett., 76, 25, 4821-4821 (1996) · doi:10.1103/PhysRevLett.76.4821
[21] G. Parisi, Recent rigorous results support the predictions of spontaneously broken replica symmetriy for realistic spin glass, preprint, March, 1996. Available as condmat preprint 9603101 at http://www.sissa.it.
[22] Rio, E., Strong Approximation for set-indexed partial-sum processes, via KMT constructions II, Ann. Prob., 21, 3, 1706-1727 (1993) · Zbl 0779.60030 · doi:10.1214/aop/1176989138
[23] Seppäläinen, T., Entropy, limit theorems, and variational principles for disordered lattice systems, Commun. Math. Phys., 171, 233-277 (1995) · Zbl 0835.60090 · doi:10.1007/BF02099271
[24] Salinas, S. R.; Wreszinski, W. F., On the Mean-Field Ising Model in a Random External Field, J. Stat. Phys., 41, 299-313 (1985) · doi:10.1007/BF01020615
[25] M. Ledoux, M. Talagrand,Probability in Banach Spaces, Springer Verlag (1991). · Zbl 0748.60004
This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. In some cases that data have been complemented/enhanced by data from zbMATH Open. This attempts to reflect the references listed in the original paper as accurately as possible without claiming completeness or a perfect matching.