Optimal graphons in the edge-2star model

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Authors: Charles Radin, Lorenzo Sadun
Cited by: 1

Abstract

In the edge-2star model with hard constraints, we prove the existence of an open set of constraint parameters, bisected by a line segment on which there are nonunique entropy-optimal graphons related by a symmetry. At each point in the open set but off the line segment, there is a unique entropy-optimizer, bipodal and varying analytically with the constraints. We also show that throughout another open set, containing a different portion of the same line of symmetry, there is instead a unique optimal graphon, varying analytically with the parameters. We explore the extent of these open sets, determining the point at which a symmetric graphon ceases to be a local maximizer of the entropy. Finally, we prove some foundational theorems in a general setting, relating optimal graphons to the Boltzmann entropy and the generic structure of large constrained random graphs.

Fields of Study & Subjects

Markov Chains and Monte Carlo Methods Theoretical and Computational Physics Topological and Geometric Data Analysis

Publication details

Journal / source
Annales de l’Institut Henri Poincaré D Combinatorics Physics and their Interactions
Publisher
European Mathematical Society - EMS - Publishing House GmbH
Volume
13
Issue
2
Pages
217–244
Publication date
7 January 2026
Language
EN