Sequential Cavity Method for Computing Free Energy and Surface Pressure
| Autor: | Dmitriy Katz, David Gamarnik |
|---|---|
| Rok vydání: | 2009 |
| Předmět: |
Cavity method
Statistical Mechanics (cond-mat.stat-mech) Additive error Computation Probability (math.PR) FOS: Physical sciences Statistical and Nonlinear Physics Statistical mechanics 60C05 05A16 82B20 Surface pressure Exponential function Lattice (order) FOS: Mathematics Mathematics - Combinatorics Applied mathematics Combinatorics (math.CO) Mathematics - Probability Condensed Matter - Statistical Mechanics Mathematical Physics Mathematics |
| Zdroj: | Journal of Statistical Physics. 137:205-232 |
| ISSN: | 1572-9613 0022-4715 |
| Popis: | We propose a new method for the problems of computing free energy and surface pressure for various statistical mechanics models on a lattice $\Z^d$. Our method is based on representing the free energy and surface pressure in terms of certain marginal probabilities in a suitably modified sublattice of $\Z^d$. Then recent deterministic algorithms for computing marginal probabilities are used to obtain numerical estimates of the quantities of interest. The method works under the assumption of Strong Spatial Mixing (SSP), which is a form of a correlation decay. We illustrate our method for the hard-core and monomer-dimer models, and improve several earlier estimates. For example we show that the exponent of the monomer-dimer coverings of $\Z^3$ belongs to the interval $[0.78595,0.78599]$, improving best previously known estimate of (approximately) $[0.7850,0.7862]$ obtained in \cite{FriedlandPeled},\cite{FriedlandKropLundowMarkstrom}. Moreover, we show that given a target additive error $\epsilon>0$, the computational effort of our method for these two models is $(1/\epsilon)^{O(1)}$ \emph{both} for free energy and surface pressure. In contrast, prior methods, such as transfer matrix method, require $\exp\big((1/\epsilon)^{O(1)}\big)$ computation effort. Comment: 33 pages, 4 figures |
| Databáze: | OpenAIRE |
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