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January 2013 Exact thresholds for Ising–Gibbs samplers on general graphs
Elchanan Mossel, Allan Sly
Ann. Probab. 41(1): 294-328 (January 2013). DOI: 10.1214/11-AOP737


We establish tight results for rapid mixing of Gibbs samplers for the Ferromagnetic Ising model on general graphs. We show that if


then there exists a constant $C$ such that the discrete time mixing time of Gibbs samplers for the ferromagnetic Ising model on any graph of $n$ vertices and maximal degree $d$, where all interactions are bounded by $\beta$, and arbitrary external fields are bounded by $Cn\log n$. Moreover, the spectral gap is uniformly bounded away from $0$ for all such graphs, as well as for infinite graphs of maximal degree $d$.

We further show that when $d\tanh\beta<1$, with high probability over the Erdős–Rényi random graph $G(n,d/n)$, it holds that the mixing time of Gibbs samplers is

\[n^{1+\Theta({1}/{\log\log n})}.\]

Both results are tight, as it is known that the mixing time for random regular and Erdős–Rényi random graphs is, with high probability, exponential in $n$ when $(d-1)\tanh\beta>1$, and $d\tanh\beta>1$, respectively. To our knowledge our results give the first tight sufficient conditions for rapid mixing of spin systems on general graphs. Moreover, our results are the first rigorous results establishing exact thresholds for dynamics on random graphs in terms of spatial thresholds on trees.


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Elchanan Mossel. Allan Sly. "Exact thresholds for Ising–Gibbs samplers on general graphs." Ann. Probab. 41 (1) 294 - 328, January 2013.


Published: January 2013
First available in Project Euclid: 23 January 2013

zbMATH: 1270.60113
MathSciNet: MR3059200
Digital Object Identifier: 10.1214/11-AOP737

Primary: 60K35
Secondary: 82B20 , 82C20

Keywords: Glauber dynamics , Ising model , phase transition

Rights: Copyright © 2013 Institute of Mathematical Statistics

Vol.41 • No. 1 • January 2013
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