{ "id": "2405.15353", "version": "v1", "published": "2024-05-24T08:45:02.000Z", "updated": "2024-05-24T08:45:02.000Z", "title": "Sharing tea on a graph", "authors": [ "J. Pascal Gollin", "Kevin Hendrey", "Hao Huang", "Tony Huynh", "Bojan Mohar", "Sang-il Oum", "Ningyuan Yang", "Wei-Hsuan Yu", "Xuding Zhu" ], "comment": "19 pages, 2 figures", "categories": [ "math.CO", "math.PR" ], "abstract": "Motivated by the analysis of consensus formation in the Deffuant model for social interaction, we consider the following procedure on a graph $G$. Initially, there is one unit of tea at a fixed vertex $r \\in V(G)$, and all other vertices have no tea. At any time in the procedure, we can choose a connected subset of vertices $T$ and equalize the amount of tea among vertices in $T$. We prove that if $x \\in V(G)$ is at distance $d$ from $r$, then $x$ will have at most $\\frac{1}{d+1}$ units of tea during any step of the procedure. This bound is best possible and answers a question of Gantert. We also consider arbitrary initial weight distributions. For every finite graph $G$ and $w \\in \\mathbb{R}_{\\geq 0}^{V(G)}$, we prove that the set of weight distributions reachable from $w$ is a compact subset of $\\mathbb{R}_{\\geq 0}^{V(G)}$.", "revisions": [ { "version": "v1", "updated": "2024-05-24T08:45:02.000Z" } ], "analyses": { "subjects": [ "05C57", "05C90", "05C22", "91D30", "91B32", "05C63" ], "keywords": [ "sharing tea", "arbitrary initial weight distributions", "finite graph", "social interaction", "consensus formation" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }