Brightwell, Graham and Winkler, Peter (2002) Hard constraints and the Bethe Lattice: adventures at the interface of combinatorics and statistical physics. In: Proceedings of the International Congress of Mathematicians: Beijing 2002, August 20-28 (International Congress of Mathematicians//Proceedings). Higher Education Pr, pp. 605-624. ISBN 9787040086904
Statistical physics models with hard constraints, such as the discrete hard-core gas model (random independent sets in a graph), are inherently combinatorial and present the discrete mathematician with a relatively comfortable setting for the study of phase transition. In this paper we survey recent work (concentrating on joint work of the authors) in which hard-constraint systems are modeled by the space $\hom(G,H)$ of homomorphisms from an infinite graph $G$ to a fixed finite constraint graph $H$. These spaces become sufficiently tractable when $G$ is a regular tree (often called a Cayley tree or Bethe lattice) to permit characterization of the constraint graphs $H$ which admit multiple invariant Gibbs measures. Applications to a physics problem (multiple critical points for symmetry-breaking) and a combinatorics problem (random coloring), as well as some new combinatorial notions, will be presented.
|Item Type:||Book Section|
|Additional Information:||© 2002 The author|
|Library of Congress subject classification:||Q Science > QA Mathematics|
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