{ "id": "2105.02312", "version": "v1", "published": "2021-05-05T20:21:42.000Z", "updated": "2021-05-05T20:21:42.000Z", "title": "Lower Bound and Exact Values for the Boundary Independence Broadcast Number of a Tree", "authors": [ "C. M. Mynhardt", "L. Neilson" ], "comment": "15 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:2104.02266", "categories": [ "math.CO" ], "abstract": "A broadcast on a nontrivial connected graph G is a function f from V(G) to the set {0,1,...,diam(G)} such that f(v) is at most the eccentricity of v for all vertices v of G. The weight of f is the sum of the function values over V(G). A vertex u hears f from v if f(v) is positive and u is within distance f(v) from v. A broadcast f is boundary independent if any vertex that hears f from two or more vertices is at distance f(v) from each such vertex v. The maximum weight of a boundary independent broadcast on G is denoted by {\\alpha}_{bn}(G). We prove a sharp lower bound on {\\alpha}_{bn}(T) for a tree T. Combined with a previously determined upper bound, this gives exact values of {\\alpha}_{bn}(T) for some classes of trees T. We also determine {\\alpha}_{bn}(T) for trees with exactly two branch vertices and use this result to demonstrate the existence of trees for which {\\alpha}_{bn} lies strictly between the lower and upper bounds.", "revisions": [ { "version": "v1", "updated": "2021-05-05T20:21:42.000Z" } ], "analyses": { "subjects": [ "05C69" ], "keywords": [ "boundary independence broadcast number", "exact values", "upper bound", "boundary independent broadcast", "sharp lower bound" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }