{ "id": "1709.08871", "version": "v1", "published": "2017-09-26T07:56:04.000Z", "updated": "2017-09-26T07:56:04.000Z", "title": "Spectral radius of a star with one long arm", "authors": [ "Hyunshik Shin" ], "comment": "5 pages", "categories": [ "math.CO" ], "abstract": "A tree is said to be starlike if exactly one vertex has degree greater than two. In this paper, we will study the spectral properties of $S(n,k \\cdot 1)$, that is, the starlike tree with $k$ branches of length 1 and one branch of length $n$. The largest eigenvalue $\\lambda_1$ of $S(n,k \\cdot 1)$ satisfies $\\sqrt{k+1} \\leq \\lambda_1 < k/\\sqrt{k-1}$. Moreover, the largest eigenvalue of $S(n,k \\cdot 1)$ is equal to the largest eigenvalue of $S(k \\cdot (n+1) )$, which is the starlike tree that has $k$ branches of length $n-1$. Using the spectral radii of $S(n,k \\cdot 1)$ we can show", "revisions": [ { "version": "v1", "updated": "2017-09-26T07:56:04.000Z" } ], "analyses": { "subjects": [ "05C50" ], "keywords": [ "spectral radius", "long arm", "largest eigenvalue", "starlike tree", "spectral properties" ], "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable" } } }