{ "id": "2212.14060", "version": "v1", "published": "2022-12-28T19:01:13.000Z", "updated": "2022-12-28T19:01:13.000Z", "title": "The optimal bound on the 3-independence number obtainable from a polynomial-type method", "authors": [ "Lord C. Kavi", "Michael W. Newman" ], "categories": [ "math.CO" ], "abstract": "A $k$-independent set in a connected graph is a set of vertices such that any two vertices in the set are at distance greater than $k$ in the graph. The $k$-independence number of a graph, denoted $\\alpha_k$, is the size of a largest $k$-independent set in the graph. Recent results have made use of polynomials that depend on the spectrum of the graph to bound the $k$-independence number. They are optimized for the cases $k=1,2$. There are polynomials that give good (and sometimes) optimal results for general $k$, including case $k=3$. In this paper, we provide the best possible bound that can be obtained by choosing a polynomial for case $k=3$.", "revisions": [ { "version": "v1", "updated": "2022-12-28T19:01:13.000Z" } ], "analyses": { "subjects": [ "05C50", "05C69" ], "keywords": [ "optimal bound", "polynomial-type method", "number obtainable", "independence number", "independent set" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }