{ "id": "2105.03466", "version": "v1", "published": "2021-05-07T18:52:55.000Z", "updated": "2021-05-07T18:52:55.000Z", "title": "Perron value and moment of rooted trees", "authors": [ "Lorenzo Ciardo" ], "comment": "19 pages, 3 figures", "categories": [ "math.CO" ], "abstract": "The Perron value $\\rho(T)$ of a rooted tree $T$ has a central role in the study of the algebraic connectivity and characteristic set, and it can be considered a weight of spectral nature for $T$. A different, combinatorial weight notion for $T$ - the moment $\\mu(T)$ - emerges from the analysis of Kemeny's constant in the context of random walks on graphs. In the present work, we compare these two weight concepts showing that $\\mu(T)$ is \"almost\" an upper bound for $\\rho(T)$ and the ratio $\\mu(T)/\\rho(T)$ is unbounded but at most linear in the order of $T$. To achieve these primary goals, we introduce two new objects associated with $T$ - the Perron entropy and the neckbottle matrix - and we investigate how different operations on the set of rooted trees affect the Perron value and the moment.", "revisions": [ { "version": "v1", "updated": "2021-05-07T18:52:55.000Z" } ], "analyses": { "subjects": [ "05C50", "05C76", "05C05", "15A18", "05C81" ], "keywords": [ "perron value", "combinatorial weight notion", "random walks", "spectral nature", "algebraic connectivity" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }