{ "id": "2311.05542", "version": "v1", "published": "2023-11-09T17:44:26.000Z", "updated": "2023-11-09T17:44:26.000Z", "title": "Counterexamples to conjectures on the occupancy fraction of graphs", "authors": [ "Stijn Cambie", "Jorik Jooken" ], "comment": "8 pages, 3 figures", "categories": [ "math.CO" ], "abstract": "The occupancy fraction of a graph is a (normalized) measure on the size of independent sets under the hard-core model, depending on a variable (fugacity) $\\lambda.$ We present a criterion for finding the graph with minimum occupancy fraction among graphs with a fixed order, and disprove five conjectures on the extremes of the occupancy fraction and (normalized) independence polynomial for certain graph classes of regular graphs with a given girth.", "revisions": [ { "version": "v1", "updated": "2023-11-09T17:44:26.000Z" } ], "analyses": { "subjects": [ "05C07", "05C31", "05C35", "05C69", "68R05", "68R10" ], "keywords": [ "conjectures", "counterexamples", "minimum occupancy fraction", "independent sets", "regular graphs" ], "note": { "typesetting": "TeX", "pages": 8, "language": "en", "license": "arXiv", "status": "editable" } } }